Video device for two television programme sources.

p0001The invention relates to video devices according to the preambles of claims 1 and 9. FIG.

p0002From psycho optical investigations it is known that the human eye to vertical resolution losses is much less sensitive than to horizontal resolution losses.

p0003Furthermore, video devices are known which can ie record on magnetic tape a television program source an image source and a plurality of audio channels and play. Such video devices operate depending on the TV standard with 50 or 60 fields per second and have their own reception and demodulation on to even record TV program broadcasts can, if no television receiver or the receiving and demodulating means available. When playing the video and audio signal in the underlying TV norm, ie turn supplied with 50 or 60 fields per second, a TV or monitor.

p0004Due to the increasing number of television programs, it is often desirable to record two programs simultaneously transmitted in parallel. However, the recent video devices are to unable.

p0005The invention is based on the object of a video apparatus according to the preamble of claim 1 such that two television program sources can be recorded on a recording medium at the same time without significant loss of image quality.

p0006Furthermore, the invention is the object of a video apparatus according to the preamble of claim 9 in such a way that two recorded TV program sources can be played individually without loss of image quality with a video device Claim 1.

p0007These objects are solved by the characterizing features of claims 1 and 9 respectively.

p0008The video apparatus according to claim 1, two television program sources can be recorded simultaneously, without two video devices or two recording media are required.

p0009Furthermore, for the recording of two television program sources requires no more recording material, as in the past for recording a television program source.

p0010The video apparatus according to claim 9 can be selectively reproduced one of the two TV sources.

p0011The features of claims 17 or 18 further both television program sources can be played simultaneously on various monitors or TV sets.

p0012Further recording and playback in standard video method are the video equipment according to claim 1 and 9 still possible.

p0013The invention makes use of the knowledge that the eye is relatively insensitive to vertical resolution losses. The viewer of a television picture, which consists of two successive fields with a total of 625 lines, a field the odd lines and a field forming the straight lines, therefore can not identify a horizontal resolution loss when the television picture consists of two identical half-frames is formed.

p0014If the video device according to claim 1, two feature films recorded, that are already being produced at 25 frames per second, so when playing this recording with a video apparatus according to claim 9 is virtually no loss of quality can be detected.

p0015For records that have been made with a video camera, the image quality of the recording is reduced only to the image quality of a movie.

p0016In the remaining subclaims further advantageous embodiments of the invention are given.

p0017The invention is explained below using an exemplary embodiment with reference to the drawings. It shows:<ul><li>Figure 1 is a block diagram of a receiving device according to a first embodiment of the video equipment according to the invention.</li><li>Figure 2 is a block diagram of a reproducing apparatus according to a first embodiment of the video equipment according to the invention.</li><li>Fig. 3, an image signal sequence diagram for the recording and reproducing apparatus of FIG. 1 and 2.</li></ul>

p0018Fig. 1 shows a block diagram of a receiving device for an inventive video device. The antenna terminal 11 of the receiver / demodulator 1, the connection for external video sources, such. As a video camera, the switch 12 and the recording device, not shown below correspond to the structure of a video apparatus according to the prior art. For the inventive recording method for recording of two video channels on a tape, each of which have an image and a mono or stereo sound Furthermore still, a receiver / demodulator 2, a field memory 6, 8, 9, two synchronization detectors 4, 6 is, a switching device 10, a controller 7, and a 3 Tonwähleinrichtung needed. The field memory is composed of an A / D converter 6, a D / A converter 9, and a digital storage device eighth

p0019The inputs of the receiver / demodulators 1, 2, which are individually tunable, are connected to the same antenna terminal eleventh At its outputs signals occur, as shown in Fig. 3A and 3B. These signals have 50 or 60 fields per second. In each vertical blanking interval between two fields is performed, a vertical pulse and during a field be made according to TV standard, a plurality of line synchronizing pulses. The vertical pulses and the line synchronizing pulses are not shown in Fig. 3.

p0020The signal of Fig. 3A is the sync detector 4 and the switching means 10, the signal of FIG. 3B supplied to the synchronization detector 5 and the A / D converter 6 of the field memory.

p0021The synchronization detectors 4, 5 indicate the vertical and horizontal sync pulses of the television program sources to the controller 7 of the field memory 6, 8, 9 on. From the synchronization detector 4 further the field identifying pulses of the first television program source may be passed on to the changeover 10th

p0022The memory device 6, 8, 9 can store a full field. The analog field is / digital analog converted from the memory means 6, 8, 9 by means of the analog / digital converter 6, and digital / transformed by the memory means 8 by means of the digital / analog converter 9 again analogously.

p0023The controller 7 performs the memory device 8 after each vertical pulse in the signal of Fig. 3B write pulses according to the line synchronizing pulses in the signal of Fig. 3B and after each vertical pulse of FIG. 3A read and output pulses corresponding to the line synchronizing pulses in the signal of Fig. 3A. This is every other field of the second video channel in Halbbildspei cher 6, 8, 9 stored and distributed simultaneously with each field of the first television program source to the switching 10th

p0024The switching device 10 is controlled by means of the vertical pulses of the first television program source so. that they instead of each second field of the first television program source is a field of said second television program source used in the signal of Fig. 3B. This results in the output of the changeover 10 of the waveform of FIG. 3C. This signal having the same vertical and Zeilensynchronimpule as the signal of Fig. 3A or 3B is transmitted to the recording means of the video recorder and recorded. To avoid potential jumps in the composite signal, the switching device 10 may be equipped with clamp stage for each input channel. the user of the video recorder Will only record a TV program source, the switching 10 can constantly be kept in the upper position in FIG. 1.

p0025The Tonwähleinrichtung 3 is supplied from the receiver / demodulator 1, 2, the respective sound signal of the television picture source 1 and 2, each consisting of two channels. In standard recording, so when recording only a single television program source, the sound channels of the first television program source may be passed by the Tonwahleinrichtung 3 to the subsequent recording device. When recording of two television program sources, only one sound channel of a television program source of the audio channels of the television program sources via the Tonwähleinrichtung 3 connected through to the subsequent recording device. The user can adjust the video device using an input device not shown the Tonwähleinrichtung 3 such that it passes on the channels desired.

p0026Fig. 2 shows a block diagram of a reproducing apparatus for an inventive video device. The reproducing apparatus is supplied to the image signal shown in FIG. 3C, and applied to the inputs of a A / D converter 53 and a sync detector 52 and to a first input of the switching device 56th Furthermore, the existing sound signal of two channels is applied to the Tonwähleinrichtung 55th

p0027The field memory 51. 53, 54 of the reproducing apparatus as the field memory 6, 8, 9 of the receiving device constructed, that is to be stored fields are / digital / analog converted analog and the digital memory has at least the one field corresponding capacity.

p0028The signal according to Fig. 3C, in turn, includes vertical and horizontal sync pulses is not shown as the signals of FIG. 3A and 3B. The synchronization detector 52 supplies the vertical and line sync pulses of the control device 50th

p0029By means of a selector 57 can set the user, whether a first or second with a receiving device according to FIG. 1 recorded or recorded with a standard procedure television program source to be played. The selector 57 provides the controller 50 according to the desired operating mode. If a standard playback are performed, the controller 50 controls the switching device 56 in such a way that the switch is kept in the upper position of FIG. 2.

p0030When playing a recorded by a recording apparatus according to FIG. 1 television program source, the controller 50, the memory device 51 according to the vertical and horizontal synchronizing the signal of Fig. 3C controls such that from the signal of Fig. 3C every second field is stored. Since alternate the fields of the first and second channels, thus they are stored according to the setting of the selector 57 either all recorded fields of the first or second television program source, in the device, the fields to be played back TV program source are stored. The field memories 51, 53, 54 is then read out in accordance with the vertical and horizontal synchronizing the signal of Fig. 3C. ie the stored field of playback TV program source is then applied to the second input of the switch 56, when the field of not be reproduced television program source is present at the first input of the switch 56th

p0031The switching device 56 is controlled by the controller 50 in accordance with the vertical pulses that it once it has been stored by the playback device coming in the field memory 51, 53, 54, the fields to be played back TV program source first according to the upstream reproducing means and then the same field, by switches. Thus arises at the output of the switching device 56 a sequence of fields shown in Fig. 3D and Fig. 3E, which has 50 or 60 fields per second, each two successive fields are equal.

p0032The output of the switching device 50 of FIG. 3D or 3E and the output of Tonwähleinrichtung 55 are supplied to an output device, such. As an impedance converter circuit or an output jack. The Tonwähleinrichtung 55 is controlled by the control device 50 such that it switches through the associated with the reproduced television program source audio channel at a standard reproducing both sound channels and upon reproduction by the reproducing apparatus according to the invention.

p0033The recording apparatus and the reproduction apparatus according to the invention, in a VCR, find a video disc player or other video device to the video recording or video playback application when this unit has two audio channels for stereo sound in standard mode. Furthermore, in video devices that can record and / or play multiple audio channels, of course, several audio channels, each television picture source are recorded.

p0034If the recording apparatus and the reproducing apparatus according to the invention arranged in a video recorder, so with a suitable interconnection can be used both for the inventive recording apparatus and for the reproducing apparatus according to the invention the individual components of the field memory, the switching means Tonwähleinrichtung and synchronization detectors.

p0035According to a second embodiment of the invention, the two simultaneously recorded television program sources can be played on two different monitors or two different monitor groups (Hotel TV) simultaneously. For this purpose, the storage device of the playback apparatus would have to be controlled such that they successively the fields of both video channels and stores the switching device is equipped with two change-over switches. With declining costs for semiconductor memory, two reproducing apparatuses according to the invention of FIG. 2 could for this purpose the video device according to the second embodiment have.

p0036Furthermore, could also be shifted in the monitors in this second embodiment, the switching means or the entire reproduction apparatus. In this case, z. B. the choice between the two video channels could also be carried out only on the monitor at the hotel TV.

p0037According to a third embodiment of the recording apparatus and the reproducing apparatus according to the invention could also be used in a television transmission between the transmitter and receiver. The transmitter would after 1 principle illustrated and the receiver operate in FIG. According to the principle illustrated in FIG. 2. With satellite transmissions of the transmission costs and transmission costs could then be reduced accordingly.

p0038Video recorder for recording a first and a second television program source on a recording medium with a recording device to record a television program source on a recording medium and a recording apparatus which alternately one field of the first and a field of the second TV program source and continuously a sound channel feeds the recording means each television program source ( Fig. 1).