Apparatus and method for recording and/or reproducing data to/from recording medium

Description of equivalent WO 2005086598 A2

0001[DESCRIPTION]

APPARATUS AND METHOD FOR RECORDING AND/OR REPRODUCING DATA

TO/FROM RECORDING MEDIUM

0004Technical Field

0005The present invention relates to a high density optical disc, and more particularly, to an

0006apparatus and method for recording and/or reproducing data to/from a recording medium.

0007Background Art

0008Optical discs are widely used for recording a large quantity of data. Among such optical

0009discs, new high density optical media (HD-DVD), such as the Blu-ray Disc (hereinafter

0010referred to as "BD") are under development, which enable long time recording and storing of

0011high definition video and audio data. Currently, a global standard technical specification of

0012the Blu-ray disc, which is considered to be a next generation HD-DVD technology as a data

0013storing solution that significantly surpasses the present DVD, is under development along

0014with other digital apparatuses.

0015Accordingly, various draft standards related to the BD is under preparation, and in succession

0016to a rewritable Blu-ray disc (BD-RE), various draft standards both for Blu-ray disc writable

0017once (BD-WO), and Blu-ray disc read only (BD-ROM) are also under development. In such

0018course of standardization process, as a method for recording and/or reproducing the BD- RE/R/ROM, recently a physical access control (PAC) method has been under discussion for

0019solving problems caused by a failure of a drive, which supports an existing version, in

0020supporting a new version when it is intended to introduce new functions for the BD-

0021RE/R/ROM into the new version.

0022Disclosure of Invention

0023Accordingly, the present invention is directed to an apparatus and method for recording

0024and/or reproducing data to/from a recording medium that substantially obviate one or more

0025problems due to limitations and disadvantages of the related art.

0026An object of the present invention is to provide a physical access control (PAC) method and a

0027method and apparatus for recording and/or reproducing data to/from a recording medium by

0028using the PAC method.

0029Additional advantages, objects, and features of the invention will be set forth in part in the

0030description which follows and in part will become apparent to those having ordinary skill in

0031the art upon examination of the following or may be learned from practice of the invention.

0032The objectives and other advantages of the invention may be realized and attained by the

0033structure particularly pointed out in the written description and claims hereof as well as the

0034appended drawings.

0035To achieve these objects and other advantages and in accordance with the purpose of the

0036invention, as embodied and broadly described herein, a recording medium having a data structure for managing a data area of the recording medium includes at least one physical

0037access control (PAC) cluster, the at least one PAC cluster including information for managing

0038recording to and/or reproducing from the recording medium, wherein each PAC cluster

0039includes a PAC header, common to each PAC cluster, and a PAC specific information area,

0040which includes information specific to each PAC cluster, wherein the PAC header includes a

0041segment information identifying at least one segment area in a user data area of the recording

0042medium by a position information of the each segment area.

0043In another aspect of the present invention, a method for recording or reproducing data on a

0044recording medium includes recording or reproducing at least one physical access control

0045(PAC) cluster, the at least one PAC cluster including information for managing recording to

0046and/or reproducing from the recording medium, each PAC cluster including segment

0047information, if a PAC cluster is an unknown one and the segment information identifies at

0048least one segment area in a user data area of the recording medium, recording to and/or

0049reproducing from the at least one segment area by the PAC information, and if a defective

0050area in the at least one segment area is replaced with a replacement area on a spare area of the

0051recording medium, recording to and/or recording from the replacement area of the spare area

0052by the PAC information.

0053In another aspect of the present invention, in a method for recording and/or reproducing data

0054to/from a recording medium in response to a command from a host, a method for recording

0055and/or reproducing data to/from a recording medium includes storing management information including PAC information read from the recording medium, determining a

0056PAC ID in the PAC information, and recording and/or reproducing data in accordance with

0057unknown PAC rules and segment information recorded on the PAC, if the determined

0058PAC ED is not sensible, and if a defective area is encountered in a segment area of the

0059segment information during the determining a PAC_ID and recording and/or reproducing

0060data, sensing information on a replacement area written thereon in replacement of the

0061defective area as a defect list (DFL) information in a defect management area (DMA), and

0062managing the replacement area identically as the segment area belonging to the defective area.

0063In a further aspect of the present invention, an apparatus for recording and/or reproducing

0064data to/from a recording medium includes a memory for storing PAC information read from

0065the recording medium, and a microcomputer for determining a PAC ED in the PAC

0066information, and recording/reproducing data in accordance with unknown PAC rules and

0067segment information recorded on the PAC, if the determined PAC_ID is not sensible, and if a

0068defective area is encountered in a segment area of the segment information during the

0069determining a PAC_ID and recording and/or reproducing data, sensing information on a

0070replacement area written thereon in replacement of the defective area from defect list (DFL)

0071information in a defect management area (DMA), and managing the replacement area

0072identically as the segment area belonging to the defective area.

0073It is to be understood that both the foregoing general description and the following detailed

0074description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

0075Brief Description of Drawings

0076The accompanying drawings, which are included to provide a further understanding of the

0077invention and are incorporated in and constitute a part of this application, illustrate

0078embodiments of the invention and together with the description serve to explain the principle

0079of the invention. In the drawings:

0080FIG. 1 illustrates physical access control (PAC) zones on a high density optical disc

0081according to the present invention;

0082FIG. 2 illustrates configurations of INFO2 zone and INFOl zone on the high density optical

0083disc according to the present invention;

0084FIG. 3 illustrates a PAC recorded on the high density optical disc according to the present

0085invention;

0086FIG. 4 illustrates a structure of a PAC on the high density optical disc according to the

0087present invention;

0088FIG. 5 illustrates a configuration of an "Unknown PAC Rules" field according to the present

0089invention;

0090FIG. 6 illustrates segment zones on the high density optical disc according to the present

0091invention;

0092FIG. 7 illustrates a PAC method of the high density optical disc according to the present invention;

0093FIG. 8 illustrates a method for recording segment position information on the high density

0094optical disc according to the present invention; and

0095FIG. 9 illustrates a block diagram of an optical recording and/or reproducing apparatus

0096according to the present invention.

0097Best Mode for Carrying Out the Invention

0098Reference will now be made in detail to the preferred embodiments of the present invention,

0099examples of which are illustrated in the accompanying drawings. Wherever possible, the

0100same reference numbers will be used throughout the drawings to refer to the same or like

0101parts. In addition, although the terms used in the present invention are selected from

0102generally known and used terms, some of the terms mentioned in the description of the

0103present invention have been selected by the applicant at his or her discretion, the detailed

0104meanings of which are described in relevant parts of the description herein. Furthermore, it is

0105required that the present invention is understood, not simply by the actual terms used but by

0106the meaning of each term lying within.

0107FIG. 1 illustrates PAC zones on a high density optical disc according to the present invention.

0108Referring to FIG. 1, the high density optical disc is sectioned and designated as, from an

0109inner circumference to an outer circumference, a lead-in zone, a data zone, and a lead-out

0110zone. At a fore end and rear end of the data zone, there may be an inner spare area (hereinafter referred to as "ISA") and an outer spare area (hereinafter referred to as "OSA"),

0111respectively. The spare areas ISA and OSA are areas for re-allocation of data to be written

0112on a defective area thereto, when the defective area occurs in the data zone. The lead-in zone

0113is sectioned, and designated as an INFO2 zone and an INFOl zone for recording various

0114kinds of information thereon. The INFO2 zone and an INFOl zone have physical access

0115control (PAC) zones, respectively.

0116For simplicity, the PAC zone assigned to the INFO2 zone is referred to as a PAC2 zone, and

0117the PAC zone assigned to the INFOl zone is referred to as a PAC1 zone. One of the PAC2

0118zone and the PAC1 zone has an original PAC recorded thereon, and the other one is a back-

0119up zone for recording a copy of the original PAC. In view of a direction of writing from the

0120inner circumference to the outer circumference of the disc, it is preferable that the original

0121PAC is recorded on the PAC2 zone, and the back-up PAC is recorded on the PAC1 zone.

0122The PAC zone, provided for solving the problems liable to happen when an old version drive

0123fails to detect functions on the disc added from a new version of drive, has an "unknown

0124rule".

0125The "unknown rule" has rules defined thereon for controlling predictable operations of the

0126disc, i.e., controls starting from basic control of read, write, and the like to linear replacement

0127of a defective zone, logical overwrite, and the like. Accordingly, an area is provided on the

0128disc where the "unknown rule" is applicable thereto, having segments for defining an entire

0129disc, or a certain portion of the disc, which will be described in more detail in a later process. Thus, by defining an area to which the old version drive has access by using the "unknown

0130rule", the new version of optical disc reduces unnecessary access operation of the old version

0131drive.

0132Moreover, by defining an accessible area on a physical area of the disc for the old version

0133drive to access by using the PAC, a data area having a user data recorded thereon can be

0134protected more robustly, and improper access from an outside of the disc, such as hacking,

0135can be protected. In the meantime, the INFO2 zone and the INFOl zone having the PAC2

0136and PAC1 zones therein in the lead-in zone will be reviewed in view of writable

0137characteristics of the high density optical disc.

0138FIG. 2 illustrates configurations of the INFO2 zone and the INFOl zone on the high density

0139optical disc according to the present invention. Referring to FIG. 2, in case of BD-RE of the

0140high density optical disc, the INFO2 zone has 256 clusters including 32 clusters of PAC2

0141zone, 32 clusters of defect management area (DMA) 2 zone for management of defects, 32

0142clusters of control data (CD) 2 zone having control information recorded thereon, and 32

0143clusters of buffer zone (BZ) 3 zone of a buffer zone. The INFOl zone includes 32 clusters of

0144BZ2 zone of a buffer area, 32 clusters of drive area which is a drive area for storing specific

0145information specific to a drive, 32 clusters of DMA1 zone for managing defects, 32 clusters

0146of CD1 zone for recording control information, and BZ1-PACI zone for utilizing as the PAC

0147zone.

0148In cεse of the high density optical disc of writable once (BD-R), the INFO2 zone has 256 clusters including a PAC2 zone, a DMA 2 zone, a CD 2 zone, and a BZ 3 zone, each with 32

0149clusters, and the INFOl zone includes a BZ2 zone, a DMA1 zone, a CD1 zone, and BZ1-

0150PACI zone, each with 32 clusters, and 128 clusters of drive area. Thus, the PAC zones of the

0151present invention are assigned to the INFO2 zone and the INFOl zone in the lead-in zone by

015232 clusters respectively according to rewritable characteristics of the high density optical disc.

0153In the PAC zone of 32 clusters, one PAC has one cluster. A structure in which one PAC is

0154recorded at a size of one cluster will be described with reference to FIG. 3.

0155FIG. 3 illustrates a structure of a PAC recorded on the high density optical disc according to

0156the present invention. Referring to FIG. 3, one PAC of one cluster size (32 sectors) includes

0157a header zone, and a specific information zone specific to an optical disc drive. The PAC

0158header zone has 384 bytes allocated to a first sector of the PAC, for recording various kinds

0159of PAC information, such as information on an "unknown PAC rule" and segments, and the

0160other area of the PAC zone has specific information specific to the optical disc drive which is

0161called "known rule" recorded thereon.

0162A detailed structure of the PAC recorded in above structure will be described with reference

0163to FIG. 4. For simplicity, in the description of the present invention, particular fields of the

0164PAC that require more detailed description will refer to drawings that illustrate the fields.

0165FIG. 4 illustrates a structure of a PAC on the high density optical disc according to the

0166present invention. Referring to FIG. 4, as described above, the PAC includes a header

0167portion applicable to all PACs, and an area having specific information specific to the drive recorded thereon.

0168In turn, the header portion includes 4 bytes of "PACJD", 4 bytes of "Unknown PAC Rules",

01691 byte of "Entire Disc Flag", 1 byte of "Number of Segments", and 32 segments "Segment_0

0170~ Segment_31" each with 8 bytes. The "PACJD" is a field for providing the present PAC

0171status and identification codes, wherein if the "PACJD" has '00 00 00 00' bits, the

0172"PACJD" indicates that the present PAC is not used, if the "PACJD" has 'FF FF FF FE'

0173bits, the "PACJD" indicates that the present PAC zone is not available for use due to reasons

0174of defects or the like, and if the "PACJD" has 'FF FF FF FF' bits, the "PACJD" indicates

0175that the present PAC zone is available for use again even if the PAC zone is used in the past.

0176Moreover, by recording the "PACJD" in bits agreed beforehand, such as '54 53 54 00' bits,

0177the "PACJD" is used as a code for determining if the disc is one that the present drive can

0178make free access. More specifically, if the present drive does not know the "PACJD"

0179applied thus, determining that this is a case when the present drive cannot understand the

0180present PAC under a reason of version mismatch, or the like, the '54 53 54 00' bits are used

0181as a code requiring reference to information recorded on the "Unknown PAC Rules" field.

0182As described above, the "Unknown PAC Rules" field is used as a field that designates an

0183operation range of the drive that cannot understand the present PAC, which will be described

0184with reference to FIG. 5.

0185FIG. 5 illustrates a configuration of an "Unknown PAC Rules" field according to the present

0186invention. Referring to FIG. 5, definition of controllability of various areas on the disc is enabled by the "Unknown PAC Rules". The "Area" on the table represents the controllable

0187areas on the disc, the "Control" represents control types, such as read/write and so on, and

0188"Number of bits" represents a number of bits required for the control. The additional bits in

0189the "Number of bits" represent cases of dual layer disc with two recording/reproduction sides.

0190For example, read/write controllability of the PAC zone can be represented with "PAC zones

01911, 2" fields, and write controllability of defect management zone can be represented with

0192"DMA Zone 1, 2" fields. Write controllability of a replacement area for a defective area can

0193be represented with a "Replacement Clusters" field, read/write controllability of a data zone

0194can be represent with a "Data Zone" field, and logical overwrite controllability can be

0195represented with a "Logical Overwrite" field.

0196Evidently, the write controllability is physically applicable only to re-writable discs BD-RE,

0197and BD-R, and, also the write controllability of a replacement area for a defective area is also

0198applicable to the re-writable discs BD-RE, and BD-R. Thus, it is required to understand that

0199the subject matter of the present invention is dependent on the re-writable characteristics of

0200the high density optical disc. By using the above described method, the "Unknown PAC

0201Rules" field enables designation of a controllable area on the disc for the drive of version

0202mismatch. Moreover, above method is applicable, not only to the drive of version mismatch,

0203but also to control of access to a particular physical area on a disc at a user's option.

0204In the meantime, the "Entire Disc Flag" field in FIG. 4 is used as a field for informing that

0205the PAC is applicable to an entire area of the disc, and the "Number of Segments" field is a field representing a number of segment area the PAC is applicable thereto. Maximum 32

0206segments can be allocated to one PAC, and information on the allocated segments is written

0207on fields of "Segment J)" to "Segment_31" each with 8 bytes. Each of the "Segment_0 ~

0208Segment_31" fields has the first PSN and the last PSN of the allocated segment area recorded

0209thereon.

0210The segment will be described in more detail with reference to the accompanying drawings.

0211FIG. 6 illustrates segment zones on the high density optical disc according to the present

0212invention. Referring to FIG. 6, if required, there can be maximum 32 segment areas on the

0213high density optical disc of the present invention, for applying the PAC thereto starting from

0214"Segment_0" in succession. In this case, by writing the first PSN which indicates a starting

0215position of the allocated segment area, and the last PSN which indicates the last position of

0216the allocated segment area on "Segment" fields of PAC2 and PAC1 zones, the optical disc

0217drive is made to know positions of the segment areas. None of the plurality of allocated

0218segments overlap, and the starting and last positions are designated at boundaries of clusters.

0219When a defective area occurs in the segment area allocated, in other words, in case of a

0220writable high density optical disc BD-RE, or WO, a data to be recorded on the defective area

0221is recorded on a replacement area, such as a spare area. In the present invention, the

0222replacement area is also defined as an area belonging to the segment area, which will be

0223described with reference to the attached drawings.

0224FIG. 7 illustrates a diagram showing a PAC method of the high density optical disc according to the present invention. Referring to FIG. 7, with regard to the segment area having the PAC

0225of the present invention applied thereto, if the defective area "A" occurs at the segment area,

0226a data to be written on the defective area "A" is written on the spare area ISA or OSA in

0227replacement, and information on the replacement is written on a defect management area

0228(DMA) in the lead-in zone as a defect list (DFL) entry. The DFL entry includes "Status 1"

0229and "Status 2" fields, for recording information on types of the DFL entries, a "Defective

0230Cluster first PSN" field for recording a first physical sector number of a defective cluster, and

0231"Replacement Cluster first PSN" for recording a first physical sector number of replacement

0232cluster.

0233The "Status 1" field has a '0000' bit recorded thereon for indicating that the defective area is

0234of a RAD (Re-Allocatable Defect) type in which the defective area is replaced normally, the

0235"Defective Cluster first PSN" field has 'a', the first PSN of the defective area, recorded

0236thereon, the "Status 2" field has a '0000' bit recorded thereon for indicating that the "Status

02372" field is not used in the case of the writable high density optical disc (in case of the high

0238density optical disc of writable once, the bit is used for indicating that one cluster has a

0239defect), and the "Replacement Cluster first PSN" field has 'b' recorded thereon, which is the

0240first physical sector number of the replacement area. In this case, since only one time of

0241writing is physically possible in the high density optical disc of writable once (WO), it is

0242preferable that the data to be written on the defective area is recorded on a temporary disc

0243management area (TDMA) on the disc separate from the DMA area as a temporary defect list (TDFL) having a structure the same with the DFL entry at first, and is written on DMA area

0244as the DFL when the user requires, or after a disc closing at the time of writing completion.

0245In the present invention, the replacement area 'B' where the data to be written on the

0246defective area 'A' is written thereon in replacement is defined as the replacement area 'B'

0247belongs to the segment the defective area 'A' belongs by using the DFL entry. Since this

0248method enables to dispense with the requirement for handling the replacement area 'B' as a

0249separate segment, waste of the segment areas a number of which is limited to 32 is prevented,

0250and effective segment management by using the PAC is made possible. Thus, though the

0251preferred embodiment of the present invention is described by taking a RAD type as an

0252example, in which replacement of the defective area is made within one cluster, it is apparent

0253in a case of a consecutive re-allocatable defect (CRD) type in which defective areas occurred

0254at a plurality of consecutive clusters are replaced that the defective area is managed in a

0255fashion identical to the segment area the defective area belongs thereto.

0256In the meantime, referring to FIG. 7, the PAC in the lead-out zone, a duplicate of the PAC of

0257an original PAC, is recorded for more robust protection of the PAC, and is recorded in an

0258INFO zone of the lead-out zone. As described above, the position information on the

0259segment area recorded on the "Segment" field by using a segment entry has the first PSN and

0260the last PSN each with 32 bits. In this instance, the position information on the segment area

0261recorded on the "Segment" field may not be represented with the first PSN and the last PSN,

0262but with physical sector numbers of clusters taking an actual recording unit on the optical disc is clusters into account, which will be described with reference to FIG. 8.

0263FIG. 8 illustrates a method for recording segment position information on the high density

0264optical disc according to the present invention. Referring to FIG. 8, with regard to the

0265plurality of segment areas managed by the PAC, a segment entry having position information

0266of each of the segment areas includes the "first PSN of the first cluster in the Segment" field

0267and the "first PSN of the last cluster in the Segment" field. More specifically, as described

0268above, since the optical disc is written in cluster units, a position of the segment area is

0269represented in cluster units, with the first physical sector number of the first cluster of the

0270segment and the first physical sector number of the last cluster of the segment. This method

0271is convenient in view of firmware for operation of the drive.

0272FIG. 9 illustrates a block diagram of an optical recording and/or reproducing apparatus

0273according to the present invention. Referring to FIG. 9, the optical recording and/or

0274reproducing apparatus includes a recording/reproducing device 10 for performing

0275recording/reproduction on the optical disc, and a host, or controller 20 for controlling the

0276recording/reproducing device 10. (Herein, the recording/reproducing device 10 is often

0277referred to as an "optical disc drive", and both terms will be used in the description of the

0278present invention).

0279More specifically, the host 20 gives a writing or reproduction order to write or reproduce

0280to/from a particular area of the optical disc to the recording/reproducing device 10, and the

0281recording/reproducing device 10 performs the recording/reproduction to/from the particular area in response to the order from the host 20. The recording/reproducing device 10 includes

0282an interface unit 12 for performing communication, such as exchange of data and order, with

0283the host 20, a pickup unit 11 for writing/reading a data to/from the optical disc directly, a data

0284processor 13 for receiving signal from the pickup unit 11 , and recovering a desired signal

0285value, or modulating a signal to be written into a signal able to be written on the optical disc,

0286and forwarding, a servo unit 14 for controlling the pickup unit 11 to read a signal from the

0287optical disc accurately, or write a signal on the optical disc accurately, a memory 15 for

0288temporary storage of various kinds of information including management information, and

0289data, and a microcomputer 16 for controlling various parts of the recording/reproducing

0290device 10.

0291A method for recording a PAC on a high density writable optical disc by using the optical

0292recording and or reproducing apparatus will now be described. Upon inserting the optical

0293disc into the optical recording and/or reproducing apparatus, all management information is

0294read from the optical disc and stored in the memory of the recording/reproducing device 10,

0295for use at the time of recording/reproduction of the optical disc. Herein, if the user desires to

0296write on a particular area of the optical disc, the host 20, which consider such desire of the

0297user as a writing order, provides information on a desired writing position to the

0298recording/reproducing device 10, along with a set of data that is to be written.

0299Then, the microcomputer 16 in the recording/reproducing device 10 receives the writing

0300order, determines if the area of the optical disc in which the host 20 desires to write is a defective area or not from the management information stored in the memory 15, and

0301performs data writing according to the writing order from the host 20 on an area which is not

0302the defective area. In this case, if it is determined that the writing on an entire disc or on the

0303particular area includes new features which a related art recording/reproducing device is not

0304provided with, leading the related art recording/reproducing device to fail to sense, or if it is

0305intended to restrict functions, such as writing or reproducing to/from the particular area of the

0306disc according to requirements requested by the user, the microcomputer 16 of the

0307recording/reproducing device 10 writes control information of the area on the PAC zone on

0308the disc as "Unknown PAC rule". The microcomputer 16 of the recording/reproducing

0309device 10 also writes PAC information, such as the P AC ID for a written state, and segment

0310information which is control information on the particular area of the disc.

0311If a defective area occurs at the segment area, by writing the data to be written on the

0312defective area on a replacement area, such as the spare area, and the like, and information on

0313this on the DMA area as a DFL entry, it is defined that the replacement area belongs to the

0314segment area to which the defective area belongs. Moreover, the position of the segment area

0315may be indicated with the first PSN and the last PSN of the cluster, or the first PSN of the

0316first cluster and the last PSN of the last cluster of the segment in cluster units. Accordingly,

0317the microcomputer 16 provides position information of the area the data is written thereon, or

0318the PAC zone, and the data to the servo unit 14 and the data processor 13, so that the writing

0319is finished at a desired position en the optical disc through the pickup unit 11. In the meantime, a method for recording and/or reproducing the high density optical disc

0320having the PAC information written by above method will be described. Upon inserting an

0321optical disc into the optical recording and/or reproducing apparatus, all management

0322information is read from the optical disc, and stored in the memory of the recording and

0323reproducing device 15, for use at the time of recording and reproduction of the optical disc.

0324The information in the memory 10 includes position information of various zones inclusive

0325of the PAC zone on the disc. Then, a PACJD field of the PAC is examined, for verifying if

0326the PACJD of the PAC of the PAC zone is a sensible PACJD. As a result of the

0327verification, if the written PACJD is sensible, determining that it is a case when the

0328recording and reproducing device having written the data on the disc has a version identical

0329to a version of the present recording and reproducing device, or a case when there is no

0330separate writing/reproduction restrictions, the recording/reproduction is performed according

0331to the order from the host 20.

0332When the sensing of a code written on the PACJD fails, determining that it is a case when

0333there are restrictions due to reasons, such as the recording and reproducing device having

0334written the data on the disc has a version different from a version of the present recording and

0335reproducing device, the recording/reproduction is preformed according to the order from the

0336host with reference to recording/reproduction restriction areas on the disc written on the

0337"Unknown PAC rule" and "Segment". In this case, if there is a defective area in the segment

0338area recorded on the "Segment", and a data to be written is written on a replacement area by the DFL information written on the DMA area, the data on the replacement area is

0339determined to be the segment area, the recording/reproducing is performed according to

0340restriction of setting of recording/reproducing of the segment area. For this, the

0341microcomputer 16 provides the position information and data according to the order of the

0342host to the servo unit 14 and the data-processor 13, so that the recording/reproduction is

0343finished at a desired position on the optical disc through the pickup unit 11.

0344The method and apparatus for recording and/or reproducing data to/from the recording

0345medium have the following advantages. The definition of an accessible area of a disc of a

0346related art version drive by using PACs permits robust protection of a data area having a user

0347data recorded thereon, to cut off improper external access from a hacker or the like. Also, the

0348PAC which manages entire data zone or the segment areas on the disc permits effective data

0349recording and reproducing to/from the high density optical disc. In addition, a method for

0350handling a case when a defect occurs at a segment area on the disc managed by the PAC is

0351suggested, to permit an effective data recording and reproducing to/from the high density

0352optical disc. And, finally, by recording position information of the segment area on the disc

0353managed by the PAC in clusters, it is convenient in view of firmware for operation of the

0354drive.

0355Industrial Applicability

0356It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions.

0357Thus, it is intended that the present invention covers the modifications and variations of this

0358invention provided they come within the scope of the appended claims and their equivalents.