Optical disks, apparatus and method for manufacturing optical disks, apparatus and method for recording data on optical disks, apparatus and method for reproducing data from optical disks, and optical

© Patent holder (s):

Sony Corporation of TOKYO, Japan (JP).

* 72) Inventor (s):

Seiji Kobayashi in Tokyo (JP). Toshihiro Fujiki in Tokyo (JP).

© Authorized representative:

Ir. AAG Land et al in THE HAGUE.

© Device and method for recording data on optical disks, device and method for reproducing data from optical disks and optical disk.

The invention relates to an optical disc manufacturing apparatus for reading recorded digital data from an optical disc comprising an encryption unit for encrypting inserted digital data according to key information, an optical disc carrier manufactured as a unit for manufacturing an optical disc carrier, on which the encrypted digital data and key information are recorded in the shape of physical shape changes, a reflective film-forming unit for forming a reflective film on the optical disc carrier, and a key information recording unit for recording key information on the optical disc carrier on which the reflective film is formed. The reflection factor of the optical disc is changed locally, causing an irregularity in the position information of each well edge, and desired data is additionally recorded according to this irregularity. Pits and the like are arranged to deviate from the center of the track to the inner / outer zone of the optical disc, thereby recording such sub data as key information KY.

LC 2007116

This patent has been granted regardless of the attached result of the prior art research and written opinion. The patent corresponds to the original documents submitted.

APPARATUS AND METHOD FOR RECORDING DATA ON OPTICAL DISCS, APPARATUS AND METHOD FOR REPRODUCING DATA ON OPTICAL DISCS AND OPTICAL DISC

The present invention relates to an apparatus and a method for manufacturing an optical disc (disc), an apparatus and a method for recording data on the optical disc and an apparatus and a method for reproducing data from the optical disc as well as the optical disc itself. For example, the present invention may find application to a compact disc, a compact disc player, an optical disc for recording audio data, and a recording device and a reproducing device useful for the optical disc.

The present invention locally changes the reflective properties of the optical disc, causing irregularities in the positional information of each well edge. d is granted so that additional desired data is recorded on the optical disc. Accordingly, various data may be recorded on the optical disc in order to be reproduced by an optical recorder for reproducing series data which cannot be illegally copied without a negative effect on the reproduction of the series of data recorded in the form of wells .

The present invention deflects bits and the like to the inner / outer region of the optical disc, thereby recording such sub data as key information and the like, so that various data can be recorded on the optical disc for reproduction by an optical pickup for reproducing series of data, where they cannot be copied illegally without an adverse effect on the reproduction of the series of data recorded in the form of series wells.

In the case of conventional compact discs (CD), series of data to be recorded is processed, then subjected to EFM modulation (eight to fourteen modulation) recording such data as audio data.

On the other hand, a management data recording zone is formed in the lead-in area contained in the inner zone of the optical disc, and the TOC (table of contents) recorded in this recording area is used for selectively reproducing desired music data and the like. A compact disc on which various types of data as described above are recorded is provided with a recording zone for the IFPI (International Federation of the Photographic Industry) code in an inner zone of the lead-in area, where these signals such as audio signals and the TOC (table of contents) applied by the user are included. This area also has such an inscription code so as the name of the producer, disc number and the like, with which the history of the compact disc can be visually checked.

Such inscription data such as a manufacturer's name, a manufacturer's name, a disc number and the like are affixed to each compact disc, so that the history of the compact disc can be visually checked and such inscription data is used to recognize illegally copied discs derived from an original disc. However, because such inscription data is recorded in such a way that it can be visually checked, this inscription data presents a problem in that the data cannot be easily reproduced by an optical pickup of the compact disc player. To solve this problem, it requires a reproduction mechanism intended for reproduction of the inscription data because it is suitable to extract this inscription data from illegally copied discs to distinguish.

The inscription data captured by these methods are usually recorded in the form of pits and checked visually if they can be duplicated by, for example, manufacturing a puncher by peeling both the protective film and the aluminum reflective film from the compact disc. This is why the compact disc cannot be protected against illegal copying.

For example, in order to overcome the above problems, Japanese Laid-Open Patent Application No. 9-67843 describes a method according to which the recording laser output is varied to vary the well width on the disc and thereby record the inherent code on the disc. .

As a first example, there is an already known method in which a recording signal on a disc is encrypted and key information for decryption is recorded as a variation of the pit width according to the work manner described in the aforementioned patent application. A reproducing device is composed such that the key information recorded in the above-described manner is detected and the cryptogram is decrypted according to the detected key information. Therefore, since the key information is not recorded on the pirate disc, the cryptogram is not decrypted and the contents of the disc cannot be reproduced normally. If a reproduction device is constructed in the manner described above, the pirate disc becomes unusable, thereby avoiding piracy.

However, there are two known methods of manufacturing a pirate disc, one in which the reproduced signal from a disc is fed to a recording unit as it is and the other method in which the physical configuration of a disc is transferred as it is. If a disc which is manufactured according to the above is the first The above example is used to create a pirate disc according to the method in which the reproduced signal is supplied to a recording unit as it is, the key information recorded in the form of pit width change is not recorded on the pirate disc although the information in the form of pit / no pit change is included in the pirate disc. It is therefore possible to avoid manufacturing a pirate disc according to the method in which the reproduced signal is fed to a recording unit as it is by using the method described in the first example. However, if a disc manufactured according to the above first example is used to produce a pirate disc according to the method in which the physical configuration of a disc is transferred, then the key information included in the change of well width is also copied. honors the pirate disc. The first example has the drawback that making a pirate disc according to the physical transfer cannot be prevented.

The second example is known as a method to solve this problem. In the second example, the test information is not included in the form of physical configuration but in the form of a change in reflectivity (reflectance). In detail, a groove is formed on an area, for example, the run-out area of ​​an optical disc, where a strong laser beam is irradiated on the reflective film of this area, changing the reflection characteristic and recording the same information as that of a hit series.

If test information is recorded in the form of a change in reflectance, the test information is recorded in the form of a reflection characteristic change of a reflective film. Because the test information is not recorded in the form of a physical configuration (put), the test information will not be copied onto the pirate disc created according to the physical transfer. Thus, this method complements the drawback of the first example and it is possible to avoid creating a pirate disc by using the method of physical transfer.

However, the second example also has the drawback that if a pirate disc is made in accordance with a method in which the reproduced signal is supplied to a recording unit as it is, the key information recorded on the lead-out area is also copied.

As described above, the respective methods of avoiding discrimination are effective only in either method of making a pirate disc. In addition, if an optical pirate disc is made according to a description other than in the previous description and method, these said methods are not effective at all.

Under such circumstances, it is the object of the present invention to provide an apparatus and a method of manufacturing an optical disc from which an optical pirate disc cannot be made by any method according to which the reproduced signal is fed directly to a recording unit and a method according to which configuration the optical disc is physically transferred, avoiding the drawbacks of conventional pirate copying methods and an optical disc employing such anti-piracy prevention and a method of reproducing an optical disc having anti-piracy prevention.

In addition to that, it will also be possible to select an illegal copy using this data if different types of data can be included in order to be reproduced with an optical recorder for audio data reproduction, where it will be difficult to copy illegally without any negative effect on the reproduction of audio data in the form of series wells.

Accordingly, it is another object of the present invention to provide an optical disc, an optical disc recording unit, an optical disc recording method, an optical reproducing device and an optical reproducing method which may contain various data for illegal copying blocking in order to be reproduced with an optical pick-up for reproducing data recorded in the form of a series of wells and wherein it is difficult to record illegally without any negative effect on the reproduction of data recorded in the format of a series of wells and the like.

According to the invention there is provided an optical disc on which digital data is recorded in the form of physical conf iguration changes, which are composed such that digital data is reproduced by reflection of an incident laser beam from the reflective film, in which the digital signal is encrypted according to a number of key information data, wherein one of the key information data is recorded on the optical disc in the form of physical configuration changes and at least one of the key information data is recorded in the form of a reflection change of the reflective film on the optical disc.

According to an aspect of the present invention there is provided an optical discrepoding method for reproduction of an optical disc having encrypted digital data included therein, the method comprising the first reproduction step of reproducing the first key information recorded on the optical disc in the form of physical configuration changes , the second reproduction step for reproducing the second key information recorded on the optical disc in the form of a change of reflectance, and a decryption step for reproducing the digital data recorded on the optical disc and decrypting the reproduced digital data using the first and second key information .

In the eleventh aspect of the present invention applied to an optical disc device or optical disc recording method, the beam strength of a recording laser beam irradiated to an optical disc is increased intermittently according to the result of the detection of the edge and the recorded signal to locally change the reflectance of the optical disc, thereby changing the timing at which the reflected beam is received, intersects, changes a predetermined reference level.

According to the present invention applied to an optical disc, the reflectance is locally adjusted so that an irregularity in the received reflected beam arises which is obtained by scanning the pits or marks by the laser beam and recording additional data according to the local change in reflectance.

The beam strength of the recording laser beam irradiated to the optical disc is intermittently increased to locally change the reflectance of the optical disc and the time at which the reflected beam crosses the predetermined reference level, thereby reproducing additional data so that the optical disc cannot be copied illegally, wherein the additional data is, for example, discrimination code included and the additional data is reproduced by processing the reproduced signal for reproduction without adversely affecting the reproduction of the data recorded in the form of a pit or marking pattern.

In the present invention as applied to an optical disc, the reflectance is locally changed to impart an irregularity to the reflected beam obtained by laser beam scanning of pits or marks, and additional data is recorded according to this local change in the reflectance, reproducing the additional data so that the optical disc is not copied illegally, furthermore, the additional data, for example, discrimination code, is recorded and the additional data is reproduced by processing the reproduction signal for reproduction without any negative effect on the reproduction of the data recorded in the form of a pitting or marking pattern.

According to another aspect of the invention according to claim 27 or 33 when applied to an optical e-disc device or an optical disc recording method, the main modulation signal is generated according to the main data and the laser beam is irradiated to the optical disc according to this main modulation signal, thereby forming a well series or a marking series thereon and generating sub-data according to the sub-data, wherein the submodulation signal is generated and the irradiation point of the laser beam is shifted to the inner / outer region of the optical disc according to this sub-modulation signal.

In addition, according to the present invention in accordance with claim 39 when applied to an optical disc, the main data is recorded according to the length of a well or mark and the interval between wells or marks along a track, then sub-data is recorded according to displacement of the pit or mark to the inner / outer region relative to from the track center.

In addition, according to the present invention according to claim 45 when applied to an optical disc device, the displacement detection signal is output and then processed with reference to the reproduction signal whereby the sub data recorded instead of a displacement of the well or marker to the inner / reference area of ​​the optical disc with reference to the track center is reproduced. The signal level of the displacement detection signal is changed in accordance with the displacement of a well or marker to the inner / outer region of the optical disc relative to the track center.

In accordance with the present invention according to claim 49 when applying to an optical disc reproduction method, the main data recorded in the form of a well series or a marking series is reproduced with the reflected beam of the laser beam irradiated to the optical disc, and then the recorded sub data is reproduced in the form of a displacement of the well or marker to the inner / outer region relative to the track center with the same reflected laser beam.

According to the configuration of the optical disc device according to claim 27 or 33, if the main modulation signal is generated according to the main data and a pit series or marking series is formed with the laser beam irradiated according to this main modulation signal, the sub-modulation signal generated according to sub-data and the irradiation point of the laser beam is moved according to this sub-modulation signal to the inner / outer region of the optical disc, whereby the sub-data can then be recorded with selection of this displacement to the inner / outer region, in order to reproduce of the main data recorded in the form of wells or not disturbing markings. The sub data can also be included in order to avoid illegal copying, and reproduced with an optical pickup for reproduction of the main data together with the assignment of different types of data for illegal copying blocking and the like.

According to the optical disc configuration according to claim 39, if the main data is recorded according to the length of a well or mark and an interval between the wells or marks along the track and sub data is recorded in the form of a displacement of pits or markings towards the inner / outer region of the optical disc relative to the track center, the main data is then properly reproduced with the choice of this displacement of the well or marker to the inner / outer zone of the optical disc. The sub data can thus also be included tene in order to make it difficult to copy illegally and to be reproduced with an optical pickup for reproduction of the main data together with the assignment of different types of data to prevent illegal copying and the like.

According to the configuration of the optical discrepending device according to claim 45, if the displacement detection signal is output and processed with reference to the reproduction signal, the recorded sub-data is produced according to the displacement of the well or marker to the inner / outer region of the optical disc relative to the track center, and wherein the main data is recorded as a well series or marker series which can be reproduced from an optical disc constructed in the manner described above, as well as the sub data recorded in the form of a displacement of well or markers to the inner / outer zone of the optical d isc, are reproduced from the same optical disc. The level of the displacement detection signal is changed in accordance with the displacement of the well or marker to the inner / outer zone of the optical disc relative to the track center.

According to the configuration of the optical disc reproduction method, if the main data recorded in the form of a pit series or a marker series is reproduced with the reflected beam of the laser beam irradiated to the optical disc and the sub data recorded in the form of a displacement of pit or markers to the inner / outer zone of the optical disc relative to the track center are reproduced with the same reflected beam from the laser beam, Both the main and sub data are reproduced from an optical disc with different types of recorded data to prevent illegal copying, in order to prevent orders reproduced with an optical pick-up for reproduction of data recorded in the form of a well series and the like, which makes it difficult to copy illegally.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a block diagram of an example of an optical disc manufacturing apparatus in accordance with an embodiment of the present invention,

Fig. 2 is a block diagram for a cutting machine for the optical disc manufacturing apparatus of FIG. 1,

Fig. 3A to 3D are diagrams for an example of an optical disc according to an embodiment of the present invention; where A is a perspective view of the optical disc, B is a lead-in zone diagram, C is a data zone diagram, and D is a lead-in zone diagram,

Fig. 4 is a block diagram for an example of an reproducing apparatus for reproducing an opti disc according to an embodiment of the present invention.

Fig. 5 is a flowchart for the operation of a system controller for the optical disc reproduction apparatus of FIG. 4,

Fig. 6 is a block diagram for an optical disc device used for processing a compact disc according to an embodiment of the present invention,

Fig. 7A to 7E are cross-sectional views and a timing chart for a compact disc processed by the optical disc device of FIG. 6,

Fig. 8A-1 to 8J-3 are schedules for the operation of the optical disc of Fig. 6,

Fig. 9 is a block diagram for a delay circuit, an edge detection circuit and a modulation circuit for the optical disc device of FIG. 6,

Fig. 10 is a block diagram for a compact disc player for reproduction of a compact disc containing o is taken by using the optical disc device of FIG. 6,

Fig. 11 is a block diagram for a disc discrimination code reproduction circuit of the compact disc player of FIG. 10,

Fig. 12 is a block diagram of an optical disc device used to form an optical disc in accordance with the embodiment of the present invention,

Fig. 13 is a block diagram of a key modulation circuit for the optical disc device of FIG. 12,

Fig. 14 is a timing chart for the operation of the key modulation circuit of FIG. 13,

Fig. 15 is a block diagram of an optical disc device for reproducing data of an optical disc formed using the optical disc device of FIG. 12,

Fig. 16 is a block diagram of a key modulation circuit for the optical disc device of FIG. 15,

Fig. 17 is a timetable v For the operation of the key modulation circuit of Fig. 16.

DESCRIPTION OF PREFERRED EMBODIMENTS (1-1) Configuration of an embodiment In the following, an optical disc manufacturing apparatus and method and an optical disc according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, an optical disc manufacturing apparatus and method in accordance with the embodiment of the present invention will be described with reference to Fig. 1. The optical disc manufacturing apparatus in this embodiment is a manufacturing apparatus compact discs (CD). In fig. 1 the digital audio signal (SA) is reproduced from a magnetic tape by a digital tape recorder 21 applied to a first encryption circuit 22 and encrypted according to a first key information signal KY1 of from the first key information generator 24. The encrypted digital audio signal SB from the first encryption circuit is passed to the second encryption circuit and encrypted according to a second key information signal from the second key information generator 25. The double-encrypted digital audio signal SC from the second encryption circuit 23 and the second key information signal KY2 from the second key information regenerator 25 are supplied to a disc carrier manufacturing unit 2, and a disc carrier on which the double-encrypted digital audio signal SC and the second key information signal KY2 are recorded in the form of convex-concave wells are manufactured in this manner.

In the cutting machine 3 for the disc carrier manufacturing unit 2, a laser beam is modulated using the double-encrypted audio signal SC from the second encryption circuit 23 and the second key information signal KY2 v From the second key information regenerator 23, a master disc 26 is then exposed to the modulated laser beam.

The exposed master disc 26 is subjected to a developing process and a coating process in a developing coating unit 27, thereby obtaining a punch tool. The punching tool 28 is placed on an injection molding machine 29, and a disc carrier 4 of plastic, for example polycarbonate, is processed by the injection molding machine 29. On the disc carrier 4 formed in the above-described manner, the double-encrypted digital audio signal SC and the key information signal KY2 are recorded in the form of a very small convex concave (pit).

Then, a reflective film is formed on the disc carrier 4 by the reflection film-forming unit 41, whereby a semi-finished disc 5 is obtained. On this semi-finished disc 5, the double-encrypted digital audio signal SC and the second key information signal KY2 from the second key generator 25 recorded in the form of a concave-convex well, and the reflective film for reflecting a laser beam is formed on the other side of the well. However, the first key information signal KY1 from the first key generator 24 is not recorded on the semi-finished disc 5. Therefore, it is impossible to reproduce the recorded music because the encryption by the first encryption circuit 22 cannot be decrypted as it is when the semi-finished disc is loaded into the optical disc player.

Finally, the semi-finished disc 5 becomes one

CD-R recording unit 7 loaded. In the CD-R recording unit 7, the first key information signal KY1 is supplied from the first key generator 24 to a computer 6, whereby the zone (lead-out zone) where the data of interest to the user is not recorded obtains in response to a command from the computer 6 and where the e first key information signal KY1 is additionally recorded from the first key information generator 24. The information signal additionally recorded by the CD-R recording unit 7 is recorded in the form of a change in the reflectance of the reflectance film formed by the reflection film-forming unit.

On the compact disc (finalized disc) 8 produced in the above-described manner, the second key information signal KY2 from the second key generator 25 and the first key information signal KY1 from the first key generator 24 are recorded in addition to the reproduced digital audio signal SA from the digital tape recorder 21 . When music or the like recorded on the compact disc 8 is reproduced by an optical disc reproducing device described further below, it is possible to extract the first key information signal KY1 and the second key information signal KY2 from the compact disc 8 where the double encryption can be decrypted and a user can listen to the music in the same way as in the case of a conventional compact disc.

The first encryption circuit 22 encrypts the digital audio signal SA according to the first key information signal KY1 from the first key generator 24 according to a DES code and generates the signal as an encrypted digital audio signal SB. The DES code is short for data encryption standard. It is a widely used encryption method. Similarly, the second encryption circuit 23 encrypts the encrypted digital audio signal SB according to the second key information KY2 generated by the second key generator 25 according to the DES code and generates it as a double encrypted audio signal SC.

The first key generator 24 and the second key generator 25 generate the first s key information signal KY1 and the second key information signal ICY2 each time a new disc is cut. It is known that a circuit for generating such a key information signal is composed, for example, of an LFSR (linear feedback shift register; linear feedback shift register).

The configuration of the cutting machine 3 according to Fig. 1 will now be described with reference to Fig. 2. The cutting machine 3 is used to record the double-encrypted digital audio signal SC and the second key information signal KY2 on the master disc 26 with the exposure of the laser beam as described above. A modulation circuit 31 processes the double-encrypted digital audio signal SC in the data process specified for the compact disc, generating an Em signal SD and outputting to an optical modulator 35. The double-encrypted digital audio signal SC is added to an error correction signal and then subjected to an interleaving process and then to EFM modulation to generate an EFM signal SD. The modulation circuit 31 brings subcode data including TOC (table of contents) from a subcode generator (not shown) into the subcode zone of the Em signal SD.

The modulation circuit 32 FM modulates the second key information signal KY2 and outputs it to the optical modulator 34 as an analog signal key information modulation signal KYD. The FM modulation includes the same principle as used for recording the address information of an optical disc, for example an MD (mini disc), and a detailed description thereof is omitted. In the FM modulation, a clock signal or the like is embedded so that, for example, the key information signal KY2 is recovered from the key information modulation signal KYD.

The modulation circuit 32 is set by a system control unit d (not shown) in order to be operated only when the cutting machine 3 is operating for inclusion in the run-in zone. Thus, the key information modulation signal KYD remains at a constant voltage and the signal is not modulated by the optical modulator 34 during a period of time during which the cutting machine 3 intersects both the data zone and the lead-out zone.

The master disc 26 is rotated by a spindle motor. The motor is controlled by the servo circuit 39. The FG signal whose signal level rises is output at any predetermined rotation angle. The FG signal is output from an FG signal generator (not shown) on the bottom of the motor 38. The servo circuit 39 controls the motor 38 such that the frequency of the FG signal is set to a predetermined frequency. As described above, the master disc 26 is rotated at a predetermined rotational speed.

A recording laser source 3 3 emits a laser beam L1 to the optical modulator 34 and the optical modulator 35. The recording laser source 33 includes, for example, a gas reader. The optical modulator 34 and the optical modulator 35 comprise an electro-acoustic optical element or the like. The optical modulator 34 changes the direction of movement of the laser beam from the recording laser source 33 in accordance with the key information modulation signal KYD from the modulation circuit 32. In other words, the optical modulator 34 affects the laser beam L2 whose emission angle is slightly changed according to the level of the key information modulation signal KYD. This modulation of the emission angle of the laser beam is used as an AOD (acoustic optical deflector.

The laser beam L2 moving in the direction changed by the key information modulation signal KYD is supplied to the optical modulator 35 and ON / OFF controlled by the optical modulator 35 according to the EFM (eight to fourteen modulation) signal SD from the modulation circuit 31 and emitted as a laser beam L3.

The mirror 36 reflects the laser beam L3 in the direction of the optical path reflected at an angle of, for example, 90 ° to the master disc 26. An objective lens 37 converges the reflected beam from the mirror 36 on the recording side of the master disc 26. The change in direction of movement (corresponding to the key information modulation signal KYD) of the laser beam L3 reflected on the mirror 36 is recorded on the disk in the form of a positional deviation from the converged beam light point.

The mirror 36 and the objective lens 37 are moved step by step by a threaded (not shown) mechanism in radial direction synchronous with the rotation of the disk 26. As described above, the converging position of the laser beam L3 s tap moves step by step from, for example, the inner region to the outer region of the master disc 2, forming a spiral track on the disc 26. The wells are successively formed on the track according to the EFM signal SD. Since the displacement direction of the laser beams L2 and L3 are modulated by the optical modulator 34 in the manner described above, the center position of the well series formed on the lead-in zone is transversely displaced from the track corresponding to the key information modulation signal KYD.

The master disk 26 is exposed to the laser beam L3 modulated in accordance with the double-encrypted digital audio signal SC and the second key information signal KY2.

The lightly exposed master disk 26 is subjected to a developing and coating process as described in Fig. 1, in which a punch tool 28 is formed. The punch tool 28 is placed on the injection molding machine 29 for forming a disc carrier 4 of such a plastic material, for example polycarbonate. The reflective film is formed on the disc carrier 4, thereby forming a semi-finished disc 5. Finally, this semi-finished disk 5 is loaded into a

CD-R recording unit 7. In the CD-R recording unit 7, the zone where the data of interest to the user is not recorded (exit zone) is made accessible in response to a command from the computer 6 and the first key information signal KY1 is additionally output from the first key generator 24 is taken. The information additionally recorded in the CD-R recording unit is recorded in the form of a change of reflectance of the reflective film formed by the reflection film-forming machine 41.

The CD-R recording unit 7 has basically the same construction as that of the commercially available CD-R unit with the exception that the CD-R unit is modified so that the exit zone is accessible.

A compact disk 8 as described above (finished disk) is schematically shown in Fig. 3A. As Fig. 3A shows, the disk 8 is divided into three zones. The inner zone as seen from the circumferential side is the entry zone {entry) LI, the intermediate zone is the data zone DA and the outer zone is the exit zone (exit) LO.

On the lead-in zone L1, the TOC information and the second key information signal KY2 used for access to the compact disc 8 are recorded. An example of a schematic image obtained when the run-in zone is observed through a microscope is shown in Fig. 33, the TOC information of which is included in the form of wells. The central position of each such well is offset slightly from the center of the track, with the second key information signal KY2 included in the displacement form.

The data zone DA is a zone where the double-encrypted digital audio signal SC is recorded.

When viewed through a microscope, this zone shows that the double-encrypted digital audio signal SC is in the form of pits, for example, as drawn in Fig. 3C. Since the second key information signal KY2 is not recorded on a data zone, the central position of each well has not been moved.

On the exit zone LO, the key information KY1 is recorded by the CD-R recording unit 7. When this zone is viewed through a microscope, it appears that the first key information signal KY1 is recorded in the form of a change in reflectance, as shown, for example, in FIG. 3D. It will be clear that the information is not included as a physical change (concave convex).

For example, it is believed that a disc-making pirate will receive a compact disc 8 manufactured as in the preamble This has been described and attempts to make a pirate disc by feeding the reproduced signal obtained from the compact disc 8 to a cutting machine. The TOC information on the entry LI, the information of the data zone and the information of the exit zone are all supplied to a cutting machine and recorded on the pirate disc. However, the second key information signal KY2 recorded in the form of a positional deviation of each well on the lead-in L1 does not appear in the reproduced signal and thus is not recorded on the pirate disc. Since the second key information signal KY2 cannot be decrypted using the pirate disc made in the manner described above, it is impossible to reproduce the music signal and the like. The pirate disc is therefore unusable and the creation of such a pirate disc by using the method described above is thus prevented.

It is then assumed that ee n Discipline maker gets a compact disc 8 and attempts to create a pirate disc using a method of physically transferring the wells. In this case, it is likely that the second key information signal KY2 recorded in the form of position deviation on the lead-in zone is transferred to the pirate disc as it is. However, the first key information signal KYI absorbed on the lead-out zone LO is recorded in the form of a change in reflectance and does not cause physical convex-concave information. Therefore, the first key information signal KY1 is not transferred to the pirate disc. Therefore, since the encryption cannot decrypt the first key information signal KY1 using the pirate disc prepared in the manner described, it is impossible to reproduce the information. Thus, the pirate disc is unusable so that the manufacture of such a disc is prevented by using the method described above.

As described above, according to the example, in accordance with embodiments of the invention, it is possible to prevent a pirate disc from being made using one of the methods in which a disc is physically transferred and the method in which the reproduced signal is directly supplied to a cutting machine.

Next, a reproduction device 50 for the reproduction of a compact disc 8 made in the manner described above will be described with reference to Fig. 4.

The reproducing device 50 of FIG. 4 is controlled by a system controller 64. The compact disc 8 is rotated by a spindle motor 51. The spindle motor 51 and an optical pickup 53 are controlled by a servo circuit 52 to perform a predetermined operation. A reproduced RF signal generated by the optical pickup 53 is applied to a binary circuit 54 primal. A balance signal PP from the optical pickup 53 is supplied to an A / D converter 61.

The binary circuit 54 compares the supplied reproduced RF signal with a predetermined cut-off level to produce a binary signal. The binary signal is applied to an EFM demodulation circuit 55. The EFM demodulation circuit 55 demodulates the EMF from the binary signal to produce an 8-bit signal and supplies the generated 8-bit signal ECC (error correction circuit) circuit 56.

The ECC circuit 56 corrects errors in the output of the Em demodulation circuit 55 according to the ECC (error correction code) added during encoding on recording. Such an error arises, for example, from a defect on the compact disc 8.

On the other hand, the A / D converter 61 digitizes (quantifies) the balance signal and supplies it to a DSP 62 as a digitally reproduced DRF. Because the balance signal PP is a signal that is proportional g is with the position deviation of the pips from the center of the track, the balance signal contains the information recorded as the second key information signal KY2. The DSP 62, which is a digital signal processing processor, processes the digitally reproduced signal DRF according to a program recorded in the internal portion and demodulates FM modulation, modulated by the modulation circuit 32, thereby finding the second key information signal KY2.

A first cryptogram processing circuit 57 decrypts the encryption applied to outputs from the ECC circuit 156 using the second key information signal KY2 determined in the manner described above. The information from which the second encryption (encrypted by the second encryption circuit 23 of Fig. 1) is decrypted is then supplied to the second encryption processing circuit 58. The signal from the ECC circuit 56 is also simultaneously supplied to a memory 63. A system controller 64 controls a memory 63 to store the first key information signal KY1 in the memory 63. Thus, the first key information signal KY1 stored in the memory 63 is supplied to the second encryption processing circuit 58, so that the second encryption processing circuit 58 can decrypt the first encryption (which is encrypted by the first encryption circuit 22 of FIG. 1).

Since the encryption is decrypted in the manner described above, the digital audio signal SA is restored on the outside of the second icon processing circuit 58. The digital audio signal SA obtained in the manner described above is converted into an analog audio signal by D / A converter 59 and supplied to an output 60 and supplied to a loudspeaker or the like to generate sound.

The decryption operation g as described above, is performed by the system controller 64. The system controller 64 is arranged such that a predetermined operation indicated by a flow chart in Fig. 5 is performed by the reproducing device 50 each time a new optical disc 8 is loaded. then decryption is consistently performed as described above.

In the process performed by the system control unit 64 of FIG. 5, the system control unit 64 first commands the respective components of the system including the servo circuit 52 in step ST-1 and instructs a focal point movement of the beam emitted by the optical pickup to the input zone LI of the optical disc 8. Then, in step ST-2, the balance signal PP from the optical pickup 53 is quantified by the A / D converter 61 and processed by the DSP 62, whereby d The information recorded when the second key information signal KY2 is decoded. Then, in step ST-3, the decoded second key information signal KY2 is applied to the output of the DSP 62 and its value is preserved. The system controller 64 issues instruction for the displacement of the focus point of the beam emitted by the optical pickup to the lead-out zone LO in step ST-4. In step ST-5, next, the system controller 64 instructs the storage of the read first key information signal KY1 in the memory 63. As described above, the first key information signal KY1 and the second key information signal KY2 are obtained, and then the system controller 64 controls the entire system to reproduce the data from the compact disc 8 for audibility.

As described above, the system controller 64 controls the entire system such that the key information recorded on the entry zone LI and the exit zone LO is read and the cryptogram decryption is performed and generated according to the sound. Accordingly, the encryption is prevented from being decrypted while strong noise is generated as sound from the speaker.

In case the compact disc 8 is a normal disc (not a pirate disc), both the first and second key information signals KY1 and KY2 are properly decoded. Therefore, the first and second cryptogram processing circuits 57 and 58 can obtain the information necessary for decryption. The output of the second cryptogram processing circuit 58 is therefore supplied to the D / A converter 59, the output of the D / A converter 59 is converted into, for example, a music signal and the user concerned can thus play the music recorded on the compact disc 8 listen.

In the event that a disc that was However, by the optical disc manufacturing apparatus of the present invention being reproduced and the reproduced signal being fed back to a cutting machine to make a pirate disc, the pirate disc does not have a second key information signal KY2 in the form of a positional deviation from the well . Therefore, when an attempt is made to reproduce the pirate disc by using an optical disc reproducing apparatus of FIG. 4, the user cannot listen to the music of such a pirate disc. In the event that a pirate disc is obtained by a method in which the physical configuration of a disc is transferred in the manner described above, the user cannot listen to the music either.

In the above example of this embodiment, although the case where the second key information KY2 is recorded in the form of a position deviation of the well is described, the the present invention is not limited to this case. For example, the second key information signal KY2 can be recorded in the form of a small change in the width of the well. In this case, an optical detection system for detecting a balance signal is not necessary for the optical disc reproducing device, thereby simplifying the construction of the optical disc reproducing device and reducing costs, (1-2) Effects of the embodiments according to the first to fifth aspects of the present invention, because an optical disc manufacturing device for manufacturing an optical disc with recorded digital data to be read by irradiation of a laser beam comprises an encryption unit for encrypting digital input data according to a plurality of key information formats, an optical disc carrier production unit for the manufacture of an optical disc carrier , on which it encrypted dig digital signal and the key information are recorded in the form of physical configuration change, a reflection film-forming unit for forming a reflection film on the optical disc carrier, and a key information recording unit for recording the key information on the optical disc carrier on which the reflection film is mounted, a optical disc making device w each the effect as described in the following. According to the first to fifth inventions, because the key information recorded using two different methods, namely physical changes in the configuration and change in the reflectance of a reflective film, an optical disc manufactured by such a manufacturing device according to the present invention cannot be duplicated not only by the use of physical transfer, nor can a pirate disc be obtained by a method in which the reproduced signal from an optical disc manufactured using the device of the present invention is fed directly to a cutting machine 25. Thus, in accordance with the optical disc manufacturing apparatus according to the first to fifth inventions, profit is protected under copyright.

According to the sixth to eighth invention, because an optical disc manufacturing method for manufacturing an optical disc with recorded digital data to be read by an irradiation with the laser beam includes an encryption step for encrypting digital input data according to a number of key information data, an optical disc carrier manufacturing step for the manufacture of an optical disc carrier on which the encrypted digital data and the key information are recorded in the form of a physical change in configuration, a reflective film forming step of reflecting film on the optical disc carrier, and a key information recording step for recording the key information on the optical disc carrier on which the reflective film is formed, obtaining an optical disc manufacturing method exhibiting the effects as described further below. In detail, according to the sixth to eighth invention, an optical disc manufactured by an optical disc manufacturing method of the present invention cannot be duplicated, not only by physical transfer, nor can a pirate disc be obtained by a method in which the reproduced signal from an optical disc manufactured using the optical disc manufacturing method of the present invention is fed directly to a cutting machine. Thus, in accordance with the optical disc manufacturing method of the sixth to eighth invention, an optical disc that provides protection v obtained by the copyright holder.

According to the ninth invention, because an optical disc contains digital data in the form of a change in physical configuration and the digital data is reproduced by reflection of an incident laser beam through the reflection film, wherein the digital signal is encrypted according to a number of key information data wherein one of the keys is recorded on the optical disc in the form of a change in physical configuration and at least one of the keys is recorded in the form of changes in reflectance of the reflective film on the optical disc, it is possible to obtain an optical disc that exhibits the effect as described in the following. According to the ninth invention, because the digital data recorded on an optical disc is encrypted according to a number of key information, one of the keys can be recorded in the form of a physical data rand in configuration on the optical disc and at least one of the key information is recorded in the form of a change in reflectance of a reflection film on the optical disc, the optical disc according to the ninth invention cannot be duplicated by physical transfer, nor can a pirate disc be obtained by a method in which the reproduced signal from an optical disc according to the present invention is fed directly to a cutting machine. Thus, according to the optical disc manufacturing method according to the ninth invention, it is possible to make an optical disc that protects the copyright of the copyright holder.

According to the tenth invention, the optical disc producing method exhibiting the effects as described below is obtained because the invention provides an optical disc producing method for reproducing data from an optical disc having digital data thereon in the form of a physical change of configuration in order to be read with a laser beam irradiated on the reflective film, wherein the digital data is encrypted according to a number of key information data, one of the key information data is recorded in the form of a physical configuration change on the optical disc, and at least one of the key information data is recorded in the form of a change in reflectance of the reflective film on the optical disc. According to the tenth invention, it is possible to obtain the optical disc reproduction method for proper decryption as well as the reproduction of the data on a disc even though the disc is subject to pirate copy protection by encryption.

(2-1) Configuration in another embodiment

Fig. 6 is a block diagram for an optical disc device according to an embodiment of the o present invention. The optical disc device 1 records a disc discrimination code ED on a compact disc 2 on which a digital audio signal has already been recorded in the form of a series of wells during a compact disc production process.

As shown in Fig. 7, a carrier 3 of the compact disc 2 (shown in Fig. 7D) is manufactured with a plastic such as polycarbonate in the same manner as is used for the production of a conventional compact disc by injection molding and a punch tool. Fine convex-concave configuration corresponding to pits and elevations is formed on the information recording side of the disc carrier 3 in the injection molding process. As in a larger view (fig. 7E) is drawn with an arrow A, a reflective recording film 4 for reflecting a laser beam is formed on the information recording side of the disc carrier 3 of the compact disc 2 by, for example, evaporation, after which a protective film 5 for protection An anti-corrosion reflective film 4 has been formed.

Such absolute time code subcode information for specifying an audio signal reproduction position is recorded in a form of repeated pits and elevations on the compact disc 2 in the same manner as with a conventional compact disc, and a laser beam L is irradiated to the reflective recording film 4 by the disc carrier 3, and the reflected beam is received with the audio signal or the like being reproduced on the compact disc 2.

CD frames are assigned for each second or repeated pits and elevations formed in the manner described above (Fig. 7A) in the same manner as used for a regular compact disc, and 98 EMF frames are assigned to each CD frame, respectively (Fig. 7A). 7B). In addition, each EFM frame is divided into 588 channel clocks, and a frame sync is assigned to the first 22 channel clocks. The base time period of the well and elevated configuration is 1 period or 1 channel clock. The well and elevated configuration is repeated as a length of an integral multiple of this basic time period and the frame sync is made up of a period of 11T.

In this embodiment, the reflective recording film is formed to produce the same film structure as that of the information recording side of a CD-R. Therefore, when a laser beam L has a strength higher than a certain level and is thereby irradiated to the compact disc 2, the reflectance of the reflective recording film 4 is irreversibly changed at a position where the laser beam is incident and the change in reflectance is detected in the form of a change in the strength of the reflected beam.

In the optical disc device 1 (Fig. 6), a system controller 10 includes a microcomputer that controls the entire operation and a disc discrimination code ED on the compact disc.

In the optical disc device 1, the motor rotates the compact disc 2 at a constant linear speed under the control of a servo circuit 12.

An optical pick-up 13A detects the reproduced signal RE from the compact disc 2 prior to the optical pick-up 13B and the optical pick-up 13B records the disc discrimination code ED on the compact disc 2 according to the process result of the reproduction signal RF detected by the optical pick-up 13A.

The optical sensors 13A and 13B are connected together by a thread mechanism during the radial movement of the compact disc 2 to irradiate the laser beam near the same track. The optical sensors 13A and 13B are under tracking control and focus control independently of each other according to the reception result of the reflected beam obtained by irradiation of the laser beam to the c compact disc 2, wherein the optical pick-up 13B scans the same position just after the optical pick-up 13A scans.

The optical pick-up 13A receives the reflected beam on a predetermined receiving element and detects the reproduction signal RF with the signal level that varies according to the change in strength of the beam of the reflected beam on the receiving plane of the receiving element. The optical pick-up 13B increases the strength of the laser beam at a predetermined time under the control of the APC (automatic power control) circuit 14, locally changing the reflectance of the film 4 of the compact disc 2.

An amplifier circuit 15 amplifies the reproduction signal RF from the optical pick-up 13A by a predetermined gain and transmits the signal. A binary forming circuit 16 makes the reproduction signal RF from the amplifier 15 a binary signal corresponding to for defined reference level 20 and supplies a binary signal BD at the outputs. A PLL circuit 17 reproduces a channel CK from the binary signal BD.

A delay circuit 22 delays the time of the binary signal BD for a period of time from the time when the optical sensor 13A scans a position to a time when the optical sensor 13B scans the same position and supplies the delayed time to the output.

A disc discrimination code generating circuit includes a subcode detection circuit 20A and a dead memory (ROM) 20B. The subcode detection circuit 20A processes the binary signal BDB, which is delayed by the delay circuit 22 for a predetermined period of time, thereby reproducing subcode information in the binary signal BDB. The disc discrimination code generating circuit 20 selectively generates the time information of minutes (AMIN) and seconds (ASEC) indicated by an absolute time of the minute, second and frame part respectively of the subcode.

At that time, the subcode detection circuit 20 also generates the reset pulse which is synchronous with the second (ASEC) time information and outputs it to a conversion circuit 21.

The minute (AMIN) and second (ASEC) time information indicating a data position on the compact disc 2 are subcode information specified herein as the standard of the compact disc 2. In other words, the minute (AMIN) time information represents the data recorded on the compact disc in minutes and takes the value from, for example, 0 to 74. The second (ASEC) time information specifies a minute unit position specified in minutes (AMIN) and more finely in seconds, and takes a value from 0 to 59, for example.

The dead memory 20B holds the disc discrimination code ED and generates the data held accordingly The minute (AMIN) and second (ASEC) time information from the subcode detection circuit 20A.

The disc discrimination code ED includes the ID information inherent in each disc, the producer information, the production data and the copy permission determination information, and further includes a sync signal to indicate the start of the disc. disc discrimination code ED and an error correction code. The dead memory 20B keeps the disc discrimination code ED as bit data and outputs 1 bit discrimination code ED for the 1 address determined by the minute (AMIN) and second (ASEC) time information. Thus, the dead memory 20B generates 1 bit of disc discrimination code ED for every second.

To generate the disc discrimination code ED and execute it as described above, in the compact disc 2.1 seconds consists of 75 CD frames and 1 CD frame consists of 98 EFM frames (fig, 8) (Al) to (A- 3) as indicated d in comparison between Fig. 7 and Fig. 8, wherein the disc discrimination code generating circuit 20 generates and transmits 1 bit disc discrimination code ED (Fig. 8D) in units of 7350 (7350 = 75 x 98) Em frames. The disc discrimination code generating circuit 20 thereby generates and transmits the disc discrimination code ED, so that at least 10 well edges on the compact disc correspond to 1 bit of the discrimination code ED.

The conversion circuit 21 scrambles and transmits the disc discrimination code ED referring to the SYNC pattern. It is difficult to find the disc discrimination code ED.

In other words, in the conversion circuit 21, a sync pattern detecting circuit 21A detects the sync pattern that repeatedly appears in the binary signal DBD from the delay circuit 22. At that time, the signal level of the binary signal DBD (FIG. 8a-4) switched corresponding to a well series formed on the compact disc 2 wherein the signal level rises at the frame sync assigned to the start of each frame during a time period of 11T and then the signal level falls back over a time period of 11T.

Thus, the sync pattern detection circuit 21A determines the signal level of the consecutive binary signal DBD referring to the channel clock CK (Fig. 8B) by using multi-coupled flip-flop circuits detecting the frame sync. In the present embodiment, the sync pattern detection circuit 21A generates a frame pulse FP (Fig. 8C) whose signal level rises during a time period T, which is a channel clock for the start of the frame sync compared to the timing of the binary signal DBD to be processed by the subcode detecting circuit 20A according to the detection result of the frame sync.

An M series generation circuit 21B includes a number of cascaded coupled flip-flops and exclusive OR circuits, provided lt is the initial value for each of the plurality of flip-flops at a time corresponding to the second (ASEC) time change according to the reset pulse from the subcode detection circuit 20A and then successively transmits the set contents synchronously with the frame pulse FP and feeds it back to a predetermined intermediate stage, MM series generating random numbers of data (MS) in which logic levels 1 and 0 occur with the same probability.

The exclusive OR circuit 21C receives the M series signal MS and the disc discrimination code ED and generates the exclusive OR signal to be used as a conversion signal MD (Fig. 8E). The exclusive OR circuit 21C generates a conversion signal MD corresponding to the logic level of the M series signal MS in case the logic level of the disc discrimination code ED is zero. On the other hand, the circuit 21C generates a conversion signal MD with the invented logi level of the M series signal MS in case the logic level of the disc discrimination code is ED 1. The exclusive OR circuit 21C modulates the disc discrimination code ED according to the M series random number.

An edge detection circuit 23 detects and transmits the timing of each pit edge formed on the compact disc 2 according to the binary signal DBD supplied from the delay circuit 22. The modulation circuit 24 gates the conversion signal MD at the time of this edge, thereby increasing the control signal MX for an APC circuit 14. Thus, the beam strength of the laser beam is increased for a moment, thereby locally changing the reflectance of the compact disc 2.

As shown in Fig. 9, the delay circuit 22 transmits the binary signal BD synchronously with the channel block CK sequentially using the predetermined stages of the cascaded coupled flip flops 22A to 220, delaying the binary signal BD and outputting the delayed signal. A number of stages of the flip-flops 22A to 220 are set such that the delay time imparted to the binary signal BD due to the transmission of the binary signal becomes equal to the time period between the time when the optical pickup 13A scans a position and the time when the optical recordings 13B scan the same position.

The edge detection circuit 23 supplies the output of the flip-flop 220 to the flip-flop 23A which is operated according to the channel clock CK and supplies the input / output of the flip-flop 23A to an AND circuit 23B. AND circuit 23B has an input terminal which is used as the inverse input, so that the logic level of the output increases when the logic level of the two inputs differs from each other. The edge detection circuit 23 detects the time when h The logic level of the binary signal BD is switched and outputs the output of the AND circuit 23B, which is the detection result as an edge detection signal EP (Fig. 8F).

The modulation circuit 24 supplies the edge detection signal EP and the conversion signal MD to the AND circuit 24A whereby the conversion signal MD is gated according to the edge detection signal EP and a conversion signal MXA (Fig. 8G) is generated whose logic level rises at the time of a well edge corresponding to the logic level of the conversion signal MD.

A D flip-flop 24B operating in accordance with the channel clock CK removes noise from the modulation signal MXA and supplies the noise-free signal MXA at ​​the output while a monostable multivibrator (MM) 24C determines the pulse width of the pulse at the output of the D-flip flop 24B and supplies the modulation pulse MX to the output (Fig. 8H).

The APC circuit 14 (Fig. 61 switches the beam strength of the laser beam emitted by the optical pick-up 13B corresponding to the modulation pulse MX from the beam strength for reproduction of the beam strength for recording. The beam strength for recording implies a beam strength sufficient to change the reflectance of the reflective film 4 of the compact disc 2.

The optical disc device 1 consequently increases the beam strength of the laser beam corresponding to the disc discrimination code ED which is modulated according to random number data MS at the time when the laser beam emitted by the optical pick-up 13B forms an edge of a pit P to form the mark M so as to cover the corresponding edge in a comprehensive manner to additionally register the discrimination code ED (fig. 81-1 and 81-21). In the compact disc 2, in the case where the disc discrimination code ED is not additionally recorded, the reproduction signal RE of the si signal in which the signal level crosses approximately the average level at the time when the edges of these wells are scanned (Fig. 8J-1) are obtained. On the other hand, in the case where the discrimination code ED is additionally recorded in the manner described above, the reproduction signal RE of the signal in which the signal level locally deviates for change in reflection at the time of pit edge scanning because the reflectance is locally changed on the corresponding edge , obtained. The deviation increases after changing the reflectance (Fig. 8J-2). The disc discrimination code ED is recorded on the compact disc 2 according to the deviation detected from the reproduction signal RE and the disc discrimination code ED is reproduced with reference to the signal level change of the reproduction signal

RF.

In the optical disc device 1, the beam strength of the laser beam which ve rLarge is set by the APC circuit 14 and the pulse width of the modulation pulse MX which controls the time period of the higher value beam strength of the laser beam is set such that the reproduction signal RF is processed with the same reliability as the conventional reproduction to generate the audio signal even though the signal form of the reproduction signal RF is changed in the manner described above, in other words, such that the reproduction signal RF is binary discriminated by a sufficient margin in phase and amplitude to appropriately generate a channel clock CK.

Fig. 10 is a block diagram for a compact disc player for reproduction of the compact disc 2. In the compact disc player 30, a spindle motor 32 rotates the compact disc 2 at a constant linear speed under the control of the servo circuit 33.

An optical pickup 34 radiates a laser beam to the compact disc and receives ng the reflected beam with a predetermined receiving element, then generates a reproduction signal RF whose signal level is changed corresponding to the beam strength of the reflected beam in the receiving area of ​​the receiving element. The signal level of the reproduction signal RF changes corresponding to each well recorded on the compact disc 2. At that time, the reflectance of the disc 2 is locally changed in accordance with each well edge according to the recorded disc discrimination code ED, and the signal level of the reproduction signal RF is thereby slightly changed corresponding to the change in reflectance due to the disc discrimination code ED.

A binary signal forming circuit 35 turns the reproduction signal RF into a binary signal referring to a predetermined reference level, thereby producing a binary signal BD.

A PLL circuit 36 ​​is operated d on the basis of the binary signal BD, whereby a channel clock CCK of the reproduction signal RF is reproduced.

An EFM demodulation circuit 37 sequentially locks the binary signal ED, referring to the channel clock CCK, thereby reproducing the data corresponding to EFM modulation signal S2. In addition, the EFM demodulation circuit 37 EFM demodulates the reproduced data and then divides the demodulated data into 8-bit segments based on frame sync and cancels the intermediate shift of each generated 8-bit signal and outputs it to ECC (error correction code) circuit 38.

The ECC circuit 38 subjects the output data to an error correction operation according to the error correction code added to the output data from the EFM demodulation circuit 37, thereby reproducing and outputting the audio data D1.

A digital / analog converter (D / A) 39 subjects the audio data D1 outputted by the ECC circuit to a digital / analog conversion process and outputs the analog audio signal S4. At that time, the digital / analog converter 39 stops the output of an audio signal S4 when it is determined that the compact disc 2 is a compact disc illegally copied under the control of a system control circuit 40.

The system control circuit 40 includes a computer for controlling the operation of the compact disc player 30. The system control circuit 40 determines whether or not the compact disc 2 is an illegally copied disc according to a disc discrimination code ED supplied from the disc discrimination code reproduction circuit 41, and if the compact disc is determined to be an illegally copied disc, the system control circuit 40 controls the digital / analog converter 39 such that the output of the audio signal 54 is terminated.

The Discrimination Code Producer Selection circuit 41 decodes and transmits the disc discrimination code ED from the reproduction signal RE.

Fig. 11 is a detailed block diagram for the disc discrimination code reproduction circuit 41. In the disc discrimination code reproduction circuit 41, the sub code detection circuit 42 checks the binary signal BD with reference to the channel clock CCK and decodes the sub code information from the binary signal BD. The subcode detection circuit 42 checks the time information that is part of the decoded subcode and generates 1-second SECP detection pulses, the signal level of which increases every time the time information changes for 1 second.

An edge detecting circuit 44 has the same construction as that of the detecting circuit 23 described above with reference to Fig. 9 and detects a change point of each well of the binary signal BD and generates an edge detecting signal EP.

A syncpa throne detection circuit 45 sequentially locks the binary signal BD sent by the channel clock CCK and discriminates the continuous logic level, thereby detecting the sync pattern and generating a frame pulse FP.

An M-series generator 46 supplies a dead memory address at the 1 second detection pulse SECP, and then accesses the built-in dead memory by incrementing the addresses one at a time at a frame pulse FP, thereby making an M-series arbitrary number of data MZ generated in accordance with the M series random numbered MS generated by the optical disc device 1.

In the disc discrimination code reproduction circuit

41, accordingly, various reference signals required for reproduction of the disc discrimination code ED are generated according to the process in the optical disc device 1.

In the disc discrimination code reproduction circuit the reproduction signal RF is subjected to an analog / digital conversion referring to the channel clock CCK in the analog / digital converter 47 and an 8-bit digital reproduction signal is generated. A polarity inverting circuit (-1) 48 inverts the polarity of the digital reproduction signal and outputs the polarity inverted signal.

A selector 49 selects and outputs the digital reproduction signal supplied directly from the analog / digital converter 47 and the digital reproduction signal whose polarity is inverted, then the signal is supplied from the polarity inverting circuit 48 corresponding to the logic level of the M series arbitrary number of data MZ from the M-series generator 46. In more detail, a selector 49 selects and outputs the digital reproduction signal which is directly supplied if the logic level of the M series is arbitrary number of data MZ 1 is. On the other hand, the selector 40 selects the digital reproduction signal with the inverted polarity if the logic level of the M series is arbitrary number of data MZ 0. Thus, the selector 49 reproduces the logic level of the disc discrimination code ED modulated with the M-series arbitrary number of data MS, according to multivalue data, thereby generating the reproduction data RX of the multivalue data.

An adder 52, which is a 16-bit digital adder, adds the reproduced data RX and the output data AX from an accumulator (ACU) 53 and supplies the sum at the output. The accumulator 53 includes a 16-bit memory to hold the output data from the adder 52 and compiles an accumulation adder together with the adder 52 because the retained data is fed back to the adder 52. The accumulator 53 clears the held data with the 1 second detection pulse SECP, and explains then the output data from the adder 52 is fixedly synchronous with the output signal EP from the edge detection circuit 44. Thus, the adder 52 accumulates the logic value corresponding to a well edge selected from logic values ​​of the reproduction data RX reproduced by the selector 49 during each second (7350 frames) of the time information converts into the subcode information, so that an accumulated value AX is generated.

A binary signal-forming circuit 54 turns the output data AX from the accumulator 53 into binary numbers according to a predetermined reference value at the time when the 1 second detection pulse SECP rises and outputs the binary data. Thus, the reproduction data RX of the discrimination code ED reproduced by the selector 49 is converted into a binary disc discrimination code ED. The disc discrimination code ED is subject to an error correction process in an ECCsc by using the error correction code added to the disc discrimination code ED so that the error corrected code appears at the output.

(2-2) The operation of another embodiment

By using the above-described configuration in the manufacturing process of a compact disc 2 in accordance with the present embodiment, a master disc is formed by an ordinary master-forming apparatus and a disc carrier 3 is made using a punch tool made on the basis of the mother disc. A reflection recording film 4 and a protective film 5 are additionally applied to the disc carrier 3, whereby the compact disc 2 (Fig. 7) is obtained. Pits and elevations of a whole multiple of the base length 30 corresponding to the predetermined base period T are repeatedly made and the digital audio signal or the like is applied to the compact di sc 2 registered.

The compact disc 2 has a reflection recording film 4 having the same structure as an information recording film of a CD-R, when a laser beam L having the beam strength higher than a predetermined value is irradiated to the compact disc 2, the reflectance of the reflection registration film 4 is irreversibly changed at a place where the laser beam irradiates, and the sub data is recorded in addition to the main data which is recorded in the form of successive pits and elevations.

In the optical disc device 1 (Fig. 6), the disc discrimination code ED is recorded on the compact disc prepared in the above-described manner, so that the disc discrimination code ED does not negatively reproduce the digital audio signal recorded in the form of successive pits and elevations.

In the optical disc device 1, he the reproduction signal RF obtained from the optical pickup 13A converted into the binary signal BD by the binary signal forming circuit 16, the channel clock CK is reproduced from the binary signal BD by the PLL circuit 17, and the binary signal BD is delayed by the delay circuit 22 according to a time difference between the time when the optical pick-up 13A scans a position and the time when the optical pick-up 13B used to record the disc discrimination code ED scans the same position.

In the optical disc device 1, a subcode is detected by the subcode detection circuit 20A from the binary signal DBD from the delay circuit 22 and the disc discrimination code ED is generated at an extremely low bit rate (down to a low value of 1 bit per 1 second) synchronous with the subcode by access to dead memory 20B according to the minute (AMIN) and second (ASEC) information in the subcode.

In the sync pattern detection circuit 21A, the sync pattern is simultaneously detected from the binary signal BDB, and the M series arbitrary number of data MS in which the logic levels 1 and 0 occur with the same probability at times synchronous with the sync pattern is generated according to the detection pattern of the sync pattern in the M-series generator 21B.

In the optical disc device 1, the exclusive OR circuit 21C also modulates the disc discrimination code ED according to the M series arbitrary number of data MS, making it difficult to find the disc discrimination code ED.

In the optical disc device 1, the edge detection circuit 23 detects (Fig. 9) also the timing when the optical pick-up 13B crosses the edge of a well and the subsequent modulation circuit 24 gates the output from the exclusive OR circuit 21C with reference to the time detection result and converts the output signal into a pulse which is obtained as the result of gate operation, wherein this gate has a limited width and wherein the conversion signal MD obtained thereby intermittently increases the beam strength of the laser beam from the optical pick-up 13B.

Accordingly, the reflectance of the reflection recording film of the compact disc 2 is locally changed at a position (Fig. 8) corresponding to the increase in the beam strength of the laser beam according to the control signal MX. At that time, the output signal from the exclusive OR circuit 21C is gated at the time when the optical pickup 133 senses the edge of a well, thereby increasing the beam strength of the laser beam and thereby forming the mark M in accordance with the output signal of the exclusive OR circuit 21C so as to span the edge of each well.

In the compact disc 2 on which a mark M is formed in the manner described above, although the irregularity of the reproduction signal RF becomes larger because the change in reflectance made as described above is very limited, the change in reflectance does not negatively affect the reproduction of the information recorded in a form of a series of pits, and the clock generated is stable and accurate, and the recorded data is correctly reproduced.

In the case of the compact disc 2, appears because the disc discrimination code ED is disturbed using the M series in which the logic levels 1 and 0 appear with the same probability in the exclusive OR circuit 21C, and the distorted disc discrimination code ED is recorded when the signal form of the reproduction signal RF is observed on an oscillograph, the information of the discrimination code ED as noise and it becomes difficult to bind the discrimination code ED. Moreover, the disc discrimination code ED is difficult to copy.

In addition to the foregoing, it is noted that because 1 bit of the disc discrimination code ED is allocated to a 1 second time period, i.e., because 1 bit is recorded spread on the total 7350 (7350 = 75 x 98) EFM frames, the disc discrimination code ED is reproduced consistently even if the reproduction signal is disturbed due to noise.

Although the digital audio signal D1 recorded in the form of a series of pits on the compact disc 2 on which ds discrimination is also recorded in the manner described above is copied using the conventional illegal copying method, the disc discrimination code ED cannot be copied .

To make the exact same illegally copied disc as the compact disc 2, it is necessary to avoid the disc discrimination To record ED in the same shape mark and to do so, a disc recording medium having a reflection recording film on which the digital audio signal D1 has previously been recorded in the form of well records in the form of a series of wells must be used. In addition, a unit with the same structure as the optical disc device 1 must be used. As a result, it is difficult to copy the disc discrimination code ED.

When the laser beam is irradiated to the compact disc 2 produced in the manner described above (Fig. 10) in the compact disc player 30, the reproduction signal RF whose signal level changes with the time corresponding to the beam strength of the reflected beam obtained by irradiating the laser beam to the compact disc 2, detects the signal level of the reproduction signal RF changes with time corresponding to the well and elevations configuration and also correspond honors with the reflectance of the compact disc 2, whereby the reproduction signal is formed into a binary signal by the circuit 35. Thus, the binary signal BD is binary discriminated against by the EFM demodulation circuit 37 and then subjected to EFM demodulation and interleaving process and an error correction process performed by the ECC circuit 38. Accordingly, the digital audio signal is reproduced.

At that time, although the signal level near each pit edge changes slightly due to the presence of the mark because the mark is formed by locally changing the reflectance on the compact disc 2, the binary signal is properly discriminated in a sufficiently practical accurate level to generate a clock signal so that reproduction is properly performed by the generated clock. Thus, the compact disc 2 is properly reproduced using an ordinary compact disc c player even when the disc discrimination code ED is recorded on this compact disc 2.

In reproducing the digital audio signal in the manner described above, the disc discrimination code reproducing circuit 41 simultaneously reproduces the code ED of the compact disc 2. If the disc discrimination code ED is not reproduced properly, the disc is considered an illegally copied disc and is the digital / analog converter 39 is controlled such that the digital / analog conversion process is ended immediately. In the reproduction of the disc discrimination code ED (Fig. 11) recorded on the compact disc 2, the sync pattern detecting circuit 45 detects the frame sync, and the M series generator 46 generates the M series random number of data MZ corresponding to the M series random number of data MS for registration referring to the detected frame sync.

The edge detection circuit 44 detects upper Also, the timing when the laser beam crosses a pit edge and the subcode detecting circuit 42 detects the timing when the subcode is operating in seconds.

The analog / digital converter 47 converts the reproduction signal RF into a digitally reproduced signal, and the selector 49 selects the digital reproduction signal or digital signal whose polarity is inverted with respect to the M series arbitrary number of data MZ, thereby reproducing the reproduced data RX which the logic level of the discrimination code ED is reproduced in the form of a surplus value data.

In the reproduction of the compact disc 2, the accumulator 53 and the adder 52 selectively accumulate the reproduction data RX corresponding to each well edge in seconds as the subcode progresses step by step. The SN ratio obtained by the reproduction result of the disc discrimination code ED is clearly improved. The binary signals v Corresponding circuit 54 turns the accumulation result into binary values ​​decoding the disc discrimination code ED, and then the disc discrimination code ED is subjected to an error correction process performed by the ECC circuit 55 and supplied to the system control circuit 40.

In the reproduction of the disc discrimination code ED, although the change in reflectance of an edge is small, the disc discrimination code ED is obtained as a total of signals obtained from many kernel edges. The disc discrimination code ED can be sufficiently and consistently decoded without any adverse effect of noise on the disc. The negative effect caused by fluctuation of the level of the entire reproduction signal is effectively avoided. When the Disc Discrimination Code ED is decoded according to the total, it is possible because the Disc Discrimination Code

ED is disturbed by the use of M. series during registration, to reproduce the disc discrimination code ED very stably.

(2-3) Effect of another embodiment

According to the configuration as described above, the laser beam is irradiated to the compact disc, thereby locally changing the reflectance of the compact disc to form an irregularity, and recording the disc discrimination code using the irregularity. Thus, the disc discrimination code is recorded to be reproduced by the optical pickup which reproduces the digital audio signal, and is not pirated without any detrimental effect on the reproduction of the digital audio signal recorded in the form of pits.

Since 1 bit of the Disc Discrimination Code is assigned to 1 second with reference to a subcode and 1 Bit of the Disc Discrimination Code is assigned to at least 10 well edges for registration, the disc discrimination code is reproduced consistently without any effect of noise on the reproduced.

Because the Disc Discrimination Code is modulated with the M-Series arbitrary data for registration, the Disc Discrimination Code is recorded in such a way that it is not easy to discriminate between noise and the Disc Discrimination Code itself. So it is difficult to find and analyze the Discrimination Code. In addition, the disc discrimination code is reproduced consistently without any effect of noise on the reproduction.

Since the signal level of the reproduction signal RE is detected under decoding discrimination code and the signal level is accumulated to remove the effect of noise mixed into the disc discrimination code in the compact disc player, the disc discrimination code ED is registered so that it cannot easily be of noise are distinguished, consistently reproduced.

Because the se lector 49 selectively processes the digital reproduction signal using M series arbitrary data MZ for reproduction of the disc discrimination code, the disc discrimination code registered so that it cannot be easily found or analyzed is consistently reproduced.

(3) Other embodiment

Although the case of the CD-R film structure applies to the reflection recording film as described in the above embodiment, the present invention is not limited to that case. For example, the phase change type film structure on the disc may find application or this type of data may additionally be recorded on a conventional compact disc if it is possible to intermittently irradiate a laser beam of sufficiently high strength.

Although the case of finding the marker that surrounds a pit edge has been described in the above embodiment, the present invention is not limited to that case. For example, this type of marking can be formed near the edge to achieve the same effect as in the above-described embodiment.

Although the M series is reset in seconds in the above embodiment, the present invention is not limited to that case. For example, the M series can be reset on any CD frame to achieve the same effect as that obtained in the above embodiment.

Although the disc discrimination code is registered in the above embodiment, the present invention is not limited to that case. For example, various data required for decryption can be recorded when the digital audio signal encrypted according to the well and elevation length is recorded, when the key information needed for encryption is recorded or when the data needed for a key counting information selection or decoding is recorded.

Although the disc discrimination code is recorded on a compact disc in the above embodiment, the present invention is not limited thereto. For example, the reproduction or copy count can be recorded in an application with a compact disc player.

Although the value accumulated by the accumulator is subject to binary discrimination for reproduction of the disc discrimination code in the above embodiment, the invention is not limited thereto. For example, the accumulated value may be subject to multi-value discrimination for reproduction.

Although the EFM-modulated digital audio signal is recorded in the above embodiment, the invention is not limited thereto. For example, the present invention can find application to various modulations, for example, 1-7 modulation, 8-16 modulation, and 27 modulation. <

Although well and elevation data is recorded in the above embodiment, the invention is not limited thereto. For example, the present invention may find application to record the desired data in the form of markings and spaces.

Although the present invention is applicable to a compact disc and audio signal recording peripheral devices in the above embodiment, the invention is not limited thereto. The invention can for instance find application with different optical discs, for instance a video disc and the associated various peripheral devices.

(4-1) Configuration of another embodiment Fig. 12 is a block diagram of the optical disc device according to another embodiment of the invention. This optical disc device 1 records audio data D1 by exposing a master disc to a laser beam. The audio data Dl obtained from the digital audio recorder.

The optical disc device 1 includes a motor 4 which rotates the master disc 2 and an FG signal generator on the bottom of the motor 4, which supplies the FG signal, which signal rises at each predetermined angle of rotation. A servo circuit 5 controls the rotational speed of the motor 4 according to the laser beam exposure location on the original disc 2, determined by this FG signal, whereby the disc 2 rotates at a predetermined rotational speed.

A recording laser element 7 comprises a gas laser element, etc., and irradiates the disc 2 with a laser beam Li. An optical modulator 8A comprises, for example, an electric acoustic / optical element. The optical modulator 8A subjects this laser beam L1 to an on / off modulation according to the EFM (eight to fourteen modulation) signal S2 output from the modulator 9 and delivers the modulated laser beam L2 to the output.

An optical deflector 8B around for example, contains an electric acoustic / optical element. The optical deflector 8B breaks the laser beam L2 from the optical deflector 8A according to the key modulation signal KS from the key modulator 10, thereby changing the irradiation direction of the laser beam L2 to the inner / outer zone of the disc 2.

The mirror 12 distributes the path of the laser beam L3 from the optical deflector 10 and thereby directs the laser beam L3 to the disc 2. The objective lens 13 converges the laser beam reflected by this mirror 12 to the recording plane of the disc 2. Both the mirror 12 and the objective lens 13 are moved step by step by means of a not drawn threading mechanism from the inner zone to the outer zone of the disc 2 in synchronization with the rotation of the disc.

The optical disc device 1 can deviate the focal point of the laser beam L3 from the inner zone to the outer sun step by step e of the disc 2, forming a spiral track on the disc. The optical disc device 1 controls the on / off status of the laser beam L1 by means of the optical deflector 8A in accordance with the EFM signal S2 during this rutting process, in which pips are successively formed. The optical disc device 1 further deflects the irradiation point of the laser beam L3 via the optical deflector 8B, thereby deflecting each well to the innermost / outermost zone of the disc according to the disc modulation signal KS.

Thus, in the optical disc device 1, each well is formed such that the deviation to the inner / outer zone of the disc 2 is minimized, thus reproducing data of an optical disc made on the basis of this master disc by controlling the tracking under influence of the same characteristic as that of the conventional compact disc player, i.e. reproduces ie of recorded data that is not disturbed by any well. More specifically, in this embodiment, the deviation of each well from the inner / outer zone of the disc is suppressed to no more than 1/50 of the track pitch even at maximum deviation.

A digital audio tape recorder 3 supplies the audio data D1 to an encryption circuit at the output

15. The circuit 15 encrypts this audio data according to the DES (Data Encryption Standard) code on the basis of the key information KY and then outputs the result to the output.

A subcode generator 16 successively generates subcode data SC and supplies this generated data SC in a predetermined format to the compact disc. A modulation circuit 9 processes the output data SI from the encryption circuit 15 as well as the subcode SC and thereby generates an EFM signal 52 in the predetermined format of the compact disc . The modulation circuit 9 adds a correction code to both the output data SI from the encryption circuit 15 and the subcode data SC, and then interleaves the data and modulates the data to generate an EFM signal S2.

In the optical disc device 1, the audio data D1 can be encrypted and recorded in the form of pits on the original disc 2.

A key modulation circuit 10 generates a key modulation signal KS from the key information KY and outputs the result at the output. Therefore, in the optical disc device 1, the key information KY is recorded according to each bit deviating to the inner / outer zone of the disc. In this optical disc device 1, the key information KY is generated by a dead memory, etc.

Fig. 13 is a block diagram and this key modulation circuit 10. In the key modulation circuit 10 of FIG. 14, the EFM signal S2 becomes (Fig. 14A) input to the PLL (Phase Coupled Loop) circuit 20 and the clock CK is reproduced (Fig. 14B) from the EFM signal S2.

A sync detection circuit 21 locks the EFM signal S2 by clock CK and determines the continued logic level of the signal S2, thereby detecting a sync pattern from the EFM signal S2. The sync circuit 21 supplies the frame clock FCK at its output whose logic level rises with each sync pattern. Thus, in the compact disc format, a sync pattern is placed at the beginning of each frame, and each frame comprises 588 channel clocks. Thus, the sync detection circuit 21 supplies the frame clock FCK at its output, the logic level of which rises in units of 588 clock signals.

A subcode detection circuit 22 checks the EFM signal 52 with the clock CK and demodulates a subcode according to the EFM signal 52. The subcode detection circuit 22 additionally checks the time information ie which is part of this demodulated subcode and outputs a 1 second SECP detection pulse, the signal level of which increases every time this time information changes for 1 second. 98 frames are thus assigned to 1 second in the compact disc format, with the subcode detection circuit at the output providing a 1 second detection pulse SECP so that its signal level rises in units of 98 pulses from the frame clock (FCK).

A counter 23 is a stepwise counter for the frame clock FCK. If the 1 second SECP detection pulse rises, the counter value CT is reset. The counter 23 is formed as a ring counter which circulates the count value CT in seconds. This count value CT is changed synchronously with the frame clock FCK.

A data selector 24 outputs the held data according to the count value CT of this counter 23, which is used as the address. The too The value CT of this counter 23 is cyclically changed in units of 98 frames per second in synchronism with the sync pattern. Thus, the data selector 24 outputs types 98 of data one at a time in synchronization with the sync pattern used as the address obtained from the counter value CT. The counter value CT of the counter 23 is cyclically changed in seconds according to the 1 second detection pulse SECP whereby the data selector 24 cyclically repeats the output of this 98 type of data in seconds.

In this embodiment, the data selector 24 outputs 98-bit data in sync with the sync pattern by repeating 1-bit data assigned to each of 98 types of data in seconds. In addition, each bit of the 54-bit key information KY is assigned to each predetermined bit of the 98-bit data and a meaningless bit is assigned to each of the remaining 44 bits. In this embodiment, word and data KZ whose value is fixed assigned to such meaningless data.

The M series generator 25 includes a number of flip-flop circuits and exclusive OR circuits connected in series, respectively. The M-series generator 25 places an initial value in each of those flip-flops according to the frame clock FCK. In addition, the M series generator 25 transmits this set data one by one synchronously with the clock CK and generates M series random number of data MS in which the logic levels 1 and 0 appear with the same probability because the values ​​are fed back between the predetermined stages. Thus, the M-series generator 25 outputs an arbitrary number of data MS which is a binary series of a pseudo-random number synchronized with the clock CK, so that the same pattern is repeated in a frame period covering 588 clock cycles.

The exclusive OR circuit (X) 27 receives the data data MS as well as the output KD from the data selector 24, and then outputs a signal MS1 from the exclusive OR circuit of MS and KD (FIG. 14C). The exclusive OR circuit 27 outputs the arbitrary number of data MS as it is if the logical value of the data KD output from the selector 24 is 0 and outputs the given MS with an inverted logic level if the logic level is 1 . Therefore, the exclusive OR circuit 27 can modulate the key information KY and compose the output KD with any number and output the modulated key information.

The flip-flop circuit 28 locks the output data MS1 from the exclusive OR circuit 27, thereby referencing the rising edge of the EFM signal S2 and outputting the locked data MS1 (FIG. 14D). In this embodiment, it corresponds because the disc 2 is exposed to the laser beam under the influence of this EFM signal S2, d The scan start edge in each well with the rising edge of the EFM signal S2 on an optical disc created on the basis of this master disc 2. The flip-flop 28 maintains the logic level of the locked data MS1 in a time period between the time when MS1 ​​is sequentially output from the exclusive OR gate 27 at the clock cycle, which is a reference period for forming each well and the time when the output data MS1 is allocated a time for starting each well is locked and the formation of at least 1 well is finished.

An amplifier 29 is an amplifier for controlling the optical deflector 8B and amplifies the output from the flip-flop 28 and supplies the amplified signal to the optical deflector 8B as a key modulation signal KS. The amplifier 29 can therefore cause the irradiation point of the laser beam to deviate in bits towards the inner / outer zone of the disc 2. In amplifier 29, the far strength factor set so that this positional deviation is limited to no more than 1/50 of the well pitch. Thus, the optical disc device 1 can be prevented from reproducing errors of data recorded in the form of series of pits.

Thus, the original disc 2 exposed to the laser beam is developed and treated for electroforming, making a master disc. This master disc is then used to produce a punch tool. This punch tool is used to make optical discs in the same manner as in conventional compact disc production.

In this embodiment, an optical disc can be manufactured such that audio data D1 is encrypted in the form of series of pits and the key information KY is recorded with a deviation from each pit P to the inner / outer zone of the optical disc (Fig. 14E- 2). In other words: with an ordinary compact disc wo Wells P are formed one by one on the center of the track according to the EFM signal 52 and audio data is recorded according to the length of each well and the interval between wells (Fig. 14E-1). In the case of the optical disc according to this embodiment, on the other hand, audio data to be recorded is already encrypted according to the length of each well and the interval between the wells, and the key information KY for decrypting the encryption of this audio data is recorded according to a deviation of each pit toward the inner or outer zone of the optical disc.

Fig. 15 is a block diagram of an optical disc device 30 for reproducing data from an optical disc 31 manufactured in the manner described above. In this optical disc device 30, a motor 32 rotates the optical disc 31 at a constant linear speed under the control of the servo circuit 33.

An o The optical pick-up 34 irradiates a laser beam on the optical disc 31 and receives the reflected laser beam with a dedicated beam receiving element, and then outputs a reproduction signal RF whose signal level changes according to the strength of the reflected laser beam on this element. The reproduction signal RF changes its level according to each well recorded on the optical disc 31.

The optical pickup 34 processes the reflected laser beam received by the beam receiving element using a so-called balance method, generating a balance signal PP whose signal level changes according to the position of each well relative to the irradiation point of the laser beam on the inner / outer optical disc zone 31. The optical pickup 34 supplies a focus error signal at the output whose signal level is changed according to the size of the focus f out.

In the servo circuit 33, this balance signal PP is used to limit the frequency bands, generating a tracking error signal whose signal level is changed according to the deviation of the irradiation point of the laser beam from the center of the track. This tracking error signal is used to control the tracking of the optical pickup 34. The servo circuit 33 controls the focusing of the optical pickup 34 using the focus error signal.

A high-pass fliter (HPF) 35 cuts off the low-frequency components of the balance signal PP and thereby removes the deviation of the irradiation point of the laser beam from the center of the track of the balance signal PP whose signal level is changed according to the position of each well relative to this track center. The high pass fliter (HPF) 35 therefore detects deviation detection signal 35 HPP, including n the signal level changes according to the deviation of each pit from the center of the track.

A binary circuit 36 ​​converts the reproduction signal RF at a predetermined reference level into binary signals, thereby generating the binary signal BD.

A PLL circuit 37 functions in accordance with this binary signal BD, thereby reproducing the channel clock CCK of the production signal RF.

An EFM demodulation circuit 38 sequentially locks the binary signal BD with reference to the channel clock CCK, thereby reproducing the data according to the EFM demodulation signal 52. The EFM demodulation circuit 38, after demodulation of this reproduced data to EFM, delimits this demodulated data in units of 8 bits with reference to the frame sync and separates each generated 8 bit signal and outputs the result to an ECC (Error Correction Code ) circuit 39.

The ECC circuit 39 corrects errors in this output data in accordance with the error correction code added to the output data from this EFM demodulation circuit 38, and then reproduces encrypted audio data and outputs the reproduced data.

A cryptogram processing circuit 40 decrypts audio data according to the key information KY detected by the key detection circuit 42 and outputs the decrypted data.

A digital / analog converter (D / A) 41 converts the digital audio data D1 from the circuit 40 into analog data and outputs the analog audio data S4.

A key detection circuit 42 processes the aberration detection signal HPP referring to the channel clock CCK and the binary signal BD, thereby reproducing the key information KY and outputting the reproduced data to the output for the cryptogram processing circuit 40.

Fig. 16 is a detailed block diagram of a key detecting circuit 42. In the key detecting circuit, the subcode detecting circuit 52 controls the binary signal BD and thereby refers to the channel clock CCK and demodulates the subcode information from this binary signal BD. The subcode detection circuit 52 additionally checks the time information that is part of the demodulated subcode information and outputs a 1 second detection pulse SECP, the signal level of which increases every time this time information changes for 1 second.

A pit detecting circuit 54 sequentially locks the binary signal BD at the time when the channel clock CCK occurs and continuously compares two locked BD signals with each other, thereby detecting the rise time of the pit according to the result of the comparison. The pit detection circuit 54 supplies an edge detection signal PT at the output well at the output time in accordance with this comparison result. The well detection circuit 54 further detects the well waste time in the same manner and outputs a center detection signal CTP around the center of each well according to the detection result of the corresponding well rise time.

A sync detection circuit 55 sequentially locks the binary signal BD with reference to the channel clock CCK and determines the continuous logic level of the binary signal BD whereby a sync pattern is detected. As shown in Figure 17, the sync detection circuit 55 generates a setting pulse FSET (Figures 17A3, 17B, and 17D) whose signal level rises for only 1 clock period at the sync pattern start time and an erase pulse FCLR (Figure 1). 17C) whose signal rises with the delay of a clock cycle counted from this setting pulse FSET and delivers these pulses to the output.

Because a sync pattern is detected in units of 588 clock cycles and 98 times per second e in the binary reproduction signal BD (FIGS. 17A1 and 17A2), the sync detection circuit 55 can output the erase pulse FCLR and the set pulse FSET to the output in sync with this sync pattern.

An M series generator 56 starts each address with reference to the erase pulse FCLR and accesses the built-in dead memory address by means of the channel clock CCK, generating M series arbitrary numbers of data MX corresponding to the M series data MS contained in the optical disc device 1 are generated.

Therefore, the key detection circuit 42 can reproduce different reference signals required for reproduction of the key information KY from the processing performed in the optical disc 1.

In the key detection circuit 42, an analog / digital (A / D) converter 57 converts analog deviation detection signal HPP into a digital HPP signal driven by the channel clock CCK and then outputs an 8-bit digital reproduction signal. A polarity reversal circuit (-1) 58 inverts the polarity of this digital reproduction signal and outputs a polarity inverted signal at the output.

A latch circuit 59 locks M-series random number data MX at a time of the edge detection signal PT and holds this data MX within a time period between the point at which the exclusive OF gate MX processes in the key modulation circuit as described in FIG. 13, that is when pitting is started, and the time when the pitting is completed.

The selector 60 selects the digital signal input directly from the A / D converter 57 or the polarity inverted digital signal input from the polarity reversal circuit 58 according to the logic level of the output MZ from the latch circuit 59 and supplies the selected signal the exit. In other word and, the selector selects and outputs the digital signal which is input directly when the logic level of MZ is 1 and the polarity inverted digital signal when the logic level of MZ is 0. Thus, this selector 60 reproduces the logic level of the key information KY (KD) modulated with the M series random numbered MS using value-added data and outputs the data RX using this value-added data.

An adder 62 is a 16-bit digital adder and adds the reproduced data RX and the output data AX from the accumulator (ACU) 63 and outputs the result at the output. The accumulator 63 includes a 16-bit memory for holding the output data with the adder 62. The accumulator 63 feeds the held data back to the adder 62 thereby forming a cumulative adder together with the adder 62. In other words, d The accumulator 63 is cleared at the erase pulse FCLR and then accumulates the output data from the adder 62 in synchronism with the output signal CTP from the pit detecting circuit 54.

The adder 62 and the accumulator 63 are combined to add or subtract the deviation value detected in the center of each well according to the M-series random numbered MS. This addition or subtraction is repeated for each frame period.

A binary signal-forming circuit 64 turns the output data AX from the accumulator 63 into binary numbers according to a predetermined reference value and supplies this binary data to the output. The circuit 64 can therefore convert the data RX reproduced from the key information KY (KD) using a surplus value data produced by the selector 60 into binary data.

A shift register (SR) 65 is a 98-bit shift register. The shift register (SR) 65 rece Binary data from binary circuit 64 sequentially receives the set pulse rise (FSE) and then transfers the data.

A flip-flop (F / F) 66 extracts the data output from the shift register 65 in a bit parallel manner when the 1 second detection pulse SECP occurs and retains the data. Therefore, the flip-flop 66 in the key detection circuit 42 can hold the data KD consisting of key information KY and fixed value data KZ. The key detection circuit 42 supplies to the output a predetermined bit which is selectively held in this flip-flop 66 and thereby supplies key information KY to the cryptogram processing circuit 40 and decrypts the encrypted audio data.

(4-2) Operation in another embodiment in the above-mentioned configuration, the optical disc device 1 (Fig. 12) exposes an original disc 2 to a laser beam during the production of the optical disc 31 and the original disc 2 developed and treated for electroforming to create a master disc. The master disc is then used to make a punch tool and an optical disc.

When a master disc 2 is laser beam exposed to the optical disc device 1, audio data D1 from the digital audio tape recorder 3 is input to the encryption circuit 15 and encrypted there using predetermined key information KY. Thus, the audio data D1 is processed so as not to be reproduced without this key information KY. After this, the audio data D1 is converted into an EFM signal 52 in the modulation circuit 9 in the same manner as with a conventional compact disc.

In the optical disc device 1, this EFM signal 52 controls the on / off status of the laser beam Li and this controlled laser beam L2 is converged sequentially from the inner zone to the outer zone of the master disc, worth A spiral track is formed on the optical disc concerned, counting from the inner zone to the outer zone. The encrypted audio data D1 is then recorded in the form of pits along this track.

Although the audio data D1 is recorded in the form of pits, the key modulation circuit 10 in the optical disc device 1 can modulate the key information KY such that it cannot be easily decrypted thereby generating a key modulation signal KS. This key modulation signal KS controls the optical deflector 8B and moves the focal point of the laser beam L3 to the inner / outer zone of the original disc 2. The key information KY is recorded in this way according to the deviation of each well to the inner / outer zone of the disc 2.

Thus, in this embodiment, it is possible to provide the audio data D1 encrypted so that they cannot be reproduced without the test information KY, as well as the test information KY, which are recorded on a medium together with the data.

The positional deviation of each well formed in the manner described above is limited to no more than 1/50 of the pitch of the track, so that the deviation of the well cannot easily be observed even using a microscope. This makes it very difficult to analyze the positional deviation of the well so that the optical disc can be effectively protected against illegal copying.

Since the positional deviation is very small, the reproduction signals can be reproduced reliably with a margin sufficient both the phase and the amplitude. Thus, the audio data D1 recorded in the form of pits can be faithfully reproduced. Such pitting deviation to the inner / outer region of the disc sometimes affects track control, but a small deviation from the well as in this embodiment never disturbs the accuracy with which the track is followed. Thus, audio data recorded in the form of pits can be reproduced accurately enough in practice.

The key information KY (Fig. 13), because 98 frames are housed in 1 second on a compact disc, is placed in the data selector 24, so that data KZ consisting of 44 meaningless fixed bits are added to the key information KY consisting of a 54-bit DES code when 1 bit of data is allocated to each frame.

The key information KY (KD) is set such that 1 bit belongs to 1 frame and is output from the data selector 24 to be circulated in seconds according to the sync pattern detected in the detection circuit 21 and the SECP detected in seconds in the subcode detection circuit 22.

At the same time, the M series generates generator 25 arbitrary number data MS, which is a binary series in which logic levels 1 and 0 occur with the same synchronous probability with the clock CK and this is repeated in frames corresponding to the FCK, indicating a detected sync pattern.

The key information KY (KD) is output from the data selector 24 and modulated with the data MS, when the exclusive OR circuit 27 obtains an exclusive OR from the key information KY (KD) and the data MS. At this time, since this data MS is a binary series in which logic levels 1 and 0 appear with the same probability, the output data from the exclusive OR circuit 27 becomes possible to make the logic levels 1 and 0 differ with almost the same probability. nen.

In the key modulation circuit 10, the output data MS1 generated in this way is locked by the flip-flop 28 at the leading edge of an EFM signal S2 wherein a bit of the output data MS1 is selectively allocated to each well on the original disk 2. For the logic level of this bit, the focal point of the laser beam L3 is moved where the inner / outer zone of the disc 2 using an optical deflector 8B so that the key information KY is recorded according to this displacement to the inner / outer zone of the disc 2.

In this embodiment, the key information KY (KD) is output from the data selector in units of a single bit per frame, and this key information KY (KD) is modulated with the data MS, moving the pit P into position. Thus, on the optical disc, the pit P is irregularly displaced mar the inner / outer zone of the optical disc 2.

Therefore, in this embodiment, the bits of the key information KY (KD) are recorded in a number of wells in a distributed manner, so that it is very difficult s to find the key information KY recorded in these wells which are randomly offset from the center of the track. More specifically, even when the data-containing sides of the optical disc are observed with a microscope, a series of bits are perceived as if modulated with noise, find it very difficult to visually find this key information KY. Since 1 bit of the key information KY is allocated to 588 channel clocks, at least 1 bit of the key information KY is recorded distributed among not less than 50 wells.

Since logic levels 1 and 0 appear with the same probability in the data MS at this time, wells moved to the inner and outer zones with respect to the center of the track with substantially the same probability are also formed.

And because this positional displacement of each well is very small, this displacement of d becomes The pit is considered a noise mixture when various signals obtained from the optical pickup are observed using a microscope. It is therefore particularly difficult to determine from the signal forms of those signals whether or not key information KY is present.

On the other hand, this displacement of each well does not cause a displacement component in the sense of a girth voltage component. Since the output data MS1 is locked by the flip-flop 28 and each well is moved in position according to the data MS1, this deviation from the well can be easily detected, although a particularly smaller SN is used for the detection. The SN is obtained by extracting the high band components from the balance signal PP for detecting the tracking error signal. Thus, the optical disc can be protected against illegal copying, while it is easily constructed to reprogram the key information KY with a conventional optical pickup.

As with the conventional compact disc player, the optical disc device 30 manufactured in the above-described manner allows the reproduction signal RE to be converted into a binary signal in the binary signal forming circuit 36 ​​and then processed in the EFM demodulation circuit 38 In addition, the errors in the signal RE can be corrected in the subsequent ECC circuit 39, thereby reproducing encrypted audio data. In the subsequent cryptogram processing circuit 40, audio data is decrypted according to the key information ICY obtained separately, so that audio signals recorded in the form of pits can be reproduced as a sound using the D / A converter 41.

In the optical disc device 30, the band of the balance signal PP which is obtained using the optical pickup er 34 bounded by the high-pass fliter 35, making it possible to detect the detection signal HPP indicating the deviation from the center, wherein the signal level is changed according to the deviation of each well to the inner / outer zone of the optical disc 2 using a simple construction.

In the optical disc device 30, this aberration detection signal HPP is processed by the key detection circuit 42, so that the key information KY can be reproduced.

In the key detecting circuit 42, the deviation detecting signal HPP is converted into a digital signal by the A / D converter 57 in channel clocks, after which the polarity is reversed by the polarity inversion circuit 58.

Both these types of digital signals are selectively input to the adder 62 according to the output data MZ. The data MZ are generated as a result of the locking of the random number data MX through the latch circuit 59 corresponding to a pit with reference to the sync pattern of the binary signal BD. The digital signal selected and input to the adder 62 is accumulated with reference to the FCLR, which is a detected sync pattern.

In the recording, the output of the A / D converter 57 is added or subtracted according to the logic level of the output of the exclusive OR circuit 27 (Fig. 13) at the rising edge of the EFM signal S2 and the accumulated value AX representing the is the result of the addition or subtraction for each frame accumulated in the accumulator 63. The accumulated value

AX in this accumulator 63, which forms a binary discrimination result, is brought into a shift register 65 when the sync pattern is started, thereby demodulating the key information KY.

Because the deviation of each well is so small and the deviation detection signal HPP that is obtained from each well accumulated for a frame such that it is subject to binary discrimination even with a very small S / N ratio, the key information KY can be reproduced after the binary discrimination with a high S / N ratio. Thus, the key information KY can be reproduced with certainty while it is being recorded and cannot be easily found.

In the key detection circuit 42, the accumulator 63 extracts data from the adder 62 corresponding to the center of each well, when the circuit 42 accumulates the signal level of the deviation detection signal HPP. Thus, the signal level of the deviation detection signal HPP is accumulated at a stable time, thereby significantly improving the key detection circuit 42 in the detection accuracy.

Illegal copying of the master optical disc as described above can also be done by h Controlling the on / off status of the laser beam using the binary signal BD output from the binary circuit 36. However, in this illegal copying, it is very difficult to obtain the key information KY depending on the displacement of each well relative to the track center to register. This makes it particularly difficult to illegally copy the master disc 31.

In the event that audio data is reproduced from an optical disc illegally copied by copying only the pits, the key information KY registered according to the deviation of pits from the track center will not be copied, so that the audio signals as encrypted noise will be executed. Therefore, the recorded music will not be reproduced normally, rendering the illegally copied optical disc unusable and thus preventing illegal copying.

In this embodiment, key information can record omen are such that it can be reproduced with an optical pick-up for audio data reproduction and not illegally copied without any negative effect on the reproduction of well-recorded audio data.

(4-3) Effect of another embodiment

According to the configuration of the optical disc device as described above, since key information is recorded in the form of pits deviating from the track center directed towards the inner / outer zone of the disc, key information is recorded and reproduced with an optical pickup intended for audio data reproduction, and the disc cannot be illegally copied illegally without any negative effect on the reproduction of audio data recorded in the form of pits. Thus, the audio data encrypted with this key information can be recorded in the form of pits and are protected against illegal copying.

Since key information is modulated with a binary series prior to registration, it is difficult to find this key information contained in the form of pits displaced from the track center so as to provide effective protection against illegal copying.

Since an M series random numbers of numbers that make logic levels 1 and 0 appear with the same probability find application for the binary series, output signals from the optical pickup are considered a noise mixture, making the recorded key information difficult to find and effective protection against illegal copying is possible.

This embodiment also makes it possible to assign 1 bit key information to at least 50 wells and to move these wells so that they deviate very slightly from the track center so that t the registered key information can be reproduced truthfully.

The logic level of binary series is used to integrate the signal level of the deviation detection signal. Thus, it is possible to reproduce the key information that has been recorded, which information has been moved very slightly relative to the track center.

Since the deviation of each well from the center of the track is limited to no more than 1/50 of the track pitch, it is difficult to find the key information recorded in the form of minor deviation wells.

(5) Other embodiment

Although one bit of key information is assigned to one frame in the above embodiment, the invention is not limited thereto. For example, a number of bit key information can be assigned to one frame and, moreover, one bit key information can be assigned to a number of frames . Instead of assigning such key information bits with reference to one frame of audio data, one bit of key information can be assigned to a number of wells.

Although a bit key information recorded is distributed over no less than 50 wells by assigning a bit key information to a frame, the invention is not limited thereto. Thus, the number of wells that can be allocated to a bit can be varied as needed. As a result of experiments, it has been found that key information can be reproduced with an S / N ratio sufficient for practical use if a bit of key information is assigned no less than 20 bits.

Although key information is recorded using additional meaningless fixed bits in the above embodiment, the invention is not limited thereto. An error correction code and / or copyright information and the like can be added gd to the key information to be registered.

Although encrypted data is recorded in the form of pits and key information required for decrypting the data is also recorded in the form of pits that deviate from the track center to the inner / outer zone of the disc in the above embodiment, the invention is not limited to that. Thus, the key information can be replaced, for example, with another type of data, for example discrimination data, to enable or disable copying.

Although the accumulated value in the accumulator is subjected to binary discrimination whereby the key information in the above embodiment is reproduced, the invention is not limited thereto. This accumulated value may be subject to capital gain discrimination. In this case, the added value discrimination can be registered in 20 wells that of the spo deviate in the middle.

Although digital audio signals are modulated into EFM signals before recording in the above embodiment, the invention is not limited thereto. For example, digital audio signals can be modulated in different modulations, e.g. 1-7, 8-1, 2-7 modulations.

Although key information is recorded over the entire surface of the optical disc in the above embodiment, the invention is not limited thereto. For example, the key information can only be registered in a limited zone, such as the entry zone.

Although desired data is included in the form of wells in the above embodiment, the invention is not limited thereto. Desired information can be registered in the form of markings.

Although the present invention applies to an optical disc for recording audio data and the peripherals whereby audio signals are recorded, the invention is not limited thereto. The invention can for instance find application on different types of optical discs, for instance a video disc as well as associated peripheral devices.

According to the optical disc device according to this embodiment, the value of any pirate version of an optical disc can be sufficiently reduced even if one of the above methods is applied, thereby avoiding the massive use of this pirated version of optical disc.

According to the present invention, since the reflectance of the optical disc is locally changed to confer an anomaly on each edge position information and desired data are additionally recorded using the anomaly, data shall be included as a diac discrimination code without any adverse effect on the reproduction of the data recorded in the form of wells nth to be reproduced by the optical pickup which serves to reproduce the data and no illegal copying can take place.

According to the present invention and since sub data is recorded as key information in the form of pits deviating from the track center to the inner / outer zone of the optical disc, according to the present invention, various data can be recorded for reproducing with an optical pickup for reproduction of data recorded in the form of wells that cannot be copied illegally.