JPH0787571B2 - Video disc recording method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a recording technique for recording a television video signal together with predetermined digital data on a video disc.

[Conventional technology]

Recently, a disc for recording information at high density has been developed and commercialized. Typical examples are video discs and digital audio discs. There are several types of the system, but in the case of an optical video disc, the spectrum is as shown in FIG. That is, the television video signal has a sync tip level of 7.6 MHz,
By modulating the frequency of the carrier wave so that the white level becomes 9.3MHz, and the accompanying left and right stereo signals, bilingual signals, and other audio signals, 2.3MHz and 2.8M
Each is recorded by frequency-modulating a carrier wave of Hz. On the other hand, the spectrum of the EFM signal of the left and right stereo audio signals converted into PCM in the optical digital audio disc occupies a band of about 2 MHz or less as shown in FIG. As mentioned above, in the video disc, the band below 2MHz is almost free, so
The EFM signal can be frequency-divided and multiplex-recorded on a video disc. The spectrum in this case is as shown in FIG. 8, and it can be seen that any signal can be sufficiently separated.

FIG. 9 shows a block diagram of a recording device for such a video disc. That is, the television image signal whose high frequency components have been pre-emphasized by the pre-emphasis circuit 1 is frequency-modulated by the FM modulator 2 and input to the adder 3. Also, the audio signals of the two channels are
After pre-emphasis by the pre-emphasis circuits 4 and 5, frequency modulation is performed by the FM modulators 6 and 7, and the adder 3
Has been entered in. Furthermore, the audio signals of the two channels are converted to digital (PCM) by the PCM encoder 8 and
EFM modulated by M encoder 9, low-pass filter 10
After the unnecessary high frequency component is removed by, the signal is input to the adder 3 via the pre-emphasis circuit 11. Therefore, in the adder 3, the FM signal of the video signal, the FM signal of the 2-channel audio signal, and the EFM signal of the 2-channel audio signal are added and multiplexed, and the level thereof is adjusted by the limiter 12, It is supplied to the optical modulator 13. As a result, the laser beam output from the laser light source 14 is modulated in accordance with the signal and is irradiated onto the recording master disk 17 rotated by the motor 16 via the objective lens 15 to record the signal.
Since a technique for forming a disc from such a recording master disc 17 is known, its detailed description is omitted.

FIG. 10 shows a block diagram of a reproducing apparatus for the disc thus formed. The disk 22 rotated by the motor 21 is irradiated with the laser beam emitted from the pickup 23 through the objective lens 24, and the reflected light is received by the pickup 23 through the objective lens 24 and a reproduction signal is output. It The reproduced RF signal is output via the amplifier 25, of which the FM carrier component of the video signal passes through the bandpass filter 26, is supplied to the FM demodulator 27, is demodulated, and then is output via the de-emphasis circuit 28. It The FM carrier components of the audio signals of the two channels are transmitted to the FM demodulator 3 via the band pass filters 29 and 30, respectively.
It is supplied to 1 and 32, FM demodulated there, and then output via de-emphasis circuits 33 and 34. Further, the EFM signal component is separated by the low-pass filter 35 and supplied to the EFM decoder 37 and the PCM decoder 38 via the de-emphasis circuit 36, where the EFM demodulation and the PCM demodulation are performed respectively and output as an analog signal. Therefore, the viewer can select and listen to the high-fidelity audio signal together with the video signal as desired.

[Problems to be solved by the invention]

By the way, it is possible to record a digital data signal as the EFM signal instead of the audio signal. Unlike a voice signal, a digital data signal is not necessarily a continuous signal, so it is considered advantageous to use a block structure. However, the clock frequency of the EFM signal is about 44.1k.
The frequency of the Hz and vertical sync signal was 29.97 Hz, and there was no simple multiple relationship between them, and it was difficult to select the position and length of each data block.

[Means for solving problems]

The video disc recording method according to claim 1 is a video disc recording method in which a television video signal and digital data are frequency-divided and multiplex-recorded on the same track. Interleaving to be recorded by detecting the position of the sync signal, dividing the digital data to be recorded into blocks, forming a block group with one or more divided blocks, and performing interleaving for each of the formed block groups. When data is generated and the generated interleaved data is sequentially recorded, the beginning of the next interleaved data to be recorded should be approximately coincident with the timing of the vertical sync signal detected after the last recording timing of the previous interleaved data. The interleaved data as a television video signal. It is recorded on the track to.

The video disc recording apparatus according to claim 2 is a video disc recording method for frequency-dividing a television video signal and digital data into multiple recording on the same track. Position detecting means for detecting the position of the vertical synchronization signal
Recording means for interleaving the transferred block group data and recording the interleaved interleaved data on a track together with a television video signal; storing digital data; dividing the stored digital data into blocks; A block group that is composed of a plurality of blocks and that is to be next interleaved by substantially matching the timing of the vertical synchronization signal detected after the last recording timing of the interleaved data recorded by the recording means last time And a memory for outputting the data of (1) to the recording means.

[Action]

According to the video disc recording method of the present invention, first, the position of the vertical synchronizing signal included in the television video signal is detected. Then, the digital data to be recorded is divided into blocks, and one or a plurality of divided blocks form a block group. Further, interleaving is performed for each configured block group to generate interleaved data to be recorded. Then, when sequentially recording the generated interleaved data, the beginning of the next interleaved data to be recorded is made to substantially coincide with the timing of the vertical synchronization signal detected after the last recording timing of the previous interleaved data. , Interleaved data is recorded on a track together with a television video signal.

Further, according to the video disc recording apparatus of the present invention, the position detecting means detects the position of the vertical synchronizing signal included in the television video signal. On the other hand, the recording means interleaves the transferred data of the block group and records the interleaved interleaved data on the track together with the television video signal. Prior to recording in the recording means, the memory stores digital data, divides the stored digital data into blocks, forms a block group by one or a plurality of divided blocks, and previously recorded by the recording means. The data of the block group to be interleaved next is output to the recording means in substantially coincidence with the timing of the vertical synchronizing signal detected after the last recording timing of the interleaved data.

Therefore, according to the present invention, since the beginning of the digital data is recorded substantially at the timing of the vertical synchronizing signal, if the vertical synchronizing signal is detected and jumpback is performed during reproduction, the block of the block relating to the previous recording can be recorded. Digital data can be reproduced and squelch can be released at the timing of this vertical synchronizing signal.

〔Example〕

(I) Configuration of Disc and Recording Device FIG. 1 shows a block diagram of the recording device of the present invention. The parts corresponding to those in FIG. Omit it. In the case of FIG. 9, the audio signals of two channels are input to the EFM encoder 9 via the PCM encoder 8, but in the present invention, the digital data signal is input to the EFM encoder 9 via the memory 41. (Of course, a changeover switch or the like may be provided so that either one of the voice signal and the digital data signal is selectively input). Reference numeral 42 is a position detecting means, which detects a predetermined position of the video signal and controls the memory 41. Other video signal pre-emphasis circuit 1, FM modulator 2,
Adder 3, two-channel audio signal pre-emphasis circuits 4, 5, FM modulators 6, 7, EFM encoder 9 low-pass filter 10 in the signal path, pre-emphasis circuit
11, a limiter 12 arranged in the signal path from the adder 3,
Light modulator 13, laser light source 14, objective lens 15, motor 16,
The structure of the recording master 17 and the like is the same as in the case of FIG.

(II) Operation of disc and recording device. Video signal and audio signal of 2 channels are pre-emphasis circuit 1, 4, 5, FM
Similar to the case described above, the frequencies are modulated by the modulators 2, 6, 7 and the adder 3 and then added. In the present invention, the position detecting means 42 detects a predetermined position of the video signal.

The detected position may be the position of an arbitrary vertical synchronizing signal, but may be, for example, the position indicated by s in FIG. 5 among the respective vertical synchronizing signals. In FIG. 5, an arrow indicates a position where the pickup can jump to reproduce a still image on a CAV disc in which a video signal of one frame (two fields) is recorded for one rotation.
In the case of a normal television video signal, an odd field (A1, B1, C1, D1, E1, F1) followed by an even field (A
Since 2, B2, C2, D2, E2, F2) form one screen, the position near the vertical sync signal changing from the even field to the odd field is the jumpable position (the fifth position).
Figure (a)). On the other hand, when a 24 film movie film per second is so-called 3-2 pulled down to form a television image signal, the same screen is recorded in two consecutive fields (a1, a2, c1, c2, e1, e2) and a part (b1, b2, b3, d1, d2, d3, f1, f2, f3) where the same screen is recorded for three consecutive fields, and you can jump for still image playback. The position is a position where the same screen is displayed two fields before and one field before (Fig. 5 (b)). Therefore, the position s detected by the position detection means 42 is the position of the sync signal one frame (2 fields) before the position of the jumpable sync signal indicated by the arrow. In the portion where the same screen is recorded for the three fields, there are two positions s, but either one is selected.

When the position detecting means 42 detects the position s, the memory 41 outputs the digital data signal which has been accumulated and stored until then. This digital data signal is supplied to the EFM encoder 9, is subjected to modulation including interleaving, and is added through the low-pass filter 10 and the pre-emphasis circuit 11 to the adder 3
Is input to and is added to the frequency-modulated video signal and audio signal. Therefore, the beginning of the digital data signal is arranged and recorded near the position corresponding to the position s of the video signal. Here, for the modulation including the above interleave, in general, scrambling, C2 encoding,
Includes signal processing such as interleaving, C1 encoding, odd delay, parity conversion, synchronization signal addition, and EFM (Eight to Fourteen) modulation. CIRC (Coss Inter
The contents are to rearrange the signal order and perform data distribution while adding an error correction code of leaved Reed-Solomon Code), and further to convert the 8-bit symbol into a 14-bit pattern.

By the way, the length of one block of the digital data signal is
It can be set to an arbitrary value such as 1 kilobyte or 2 kilobytes. For example, according to the block length (98 frames (1 frame is 24 bytes)) of the audio signal before EFM modulation in the optical digital audio disc. , 2.352 kilobytes (= 24 × 98), that is, 18.816 kilobits of digital data signal as one block, and the length before interleaving is, for example, about 13.3 ms,
Since the dispersion due to the interleaving of the EFM encoder of the optical digital audio disk extends for about 14.7 ms, the length after interleaving one block is about 28 ms. Vertical sync signal interval (1 field length) is approx.
Since it is 16.7 ms, the length of one block before interleaving is shorter than the interval (vertical field length) of the vertical sync signal, but the length after interleaving is longer than the length of one field, and one frame (two fields). Shorter than the length of. Therefore, for example, the digital data signal of 5 blocks corresponding to the video signals A and B of 2 frames (FIG. 4 (a))
When D _{1 to} D ₅ (FIG. 4 (b)) are interleaved and recorded, the beginning of the interleaved first block D ₁ ′ is the vertical sync signal (at the beginning of the first field A ₁ of the frame A ( It is recorded in the vicinity of the position corresponding to FIG. However, since it is preferable to jump back during reproduction in the vertical blanking interval, it is preferable not to record the digital data signal in the vertical blanking interval including the vertical synchronization signal. Then, the block signals adjacent to each other are convoluted, and the terminal end of the last block D ₂ ′ after interleaving is located at a position corresponding to the first field C ₁ of the next frame C that does not necessarily correspond in content. Becomes (fourth
Figure (c)).

(III) Configuration of Playback Device FIG. 2 shows a block diagram of the playback device. In FIG. 2, parts corresponding to those in FIG. 10 are designated by the same reference numerals, and detailed description thereof will be omitted. . In the reproducing apparatus of the present invention, the output of the EFM decoder 37 is supplied to the data decoder 52 or the PCM decoder 38 via the switch 51. The switch 51 responds to a command from a microcomputer or the like (not shown) on the PCM decoder 38 side when an audio signal is recorded as an EFM signal, and on the data decoder 52 side when a digital data signal is recorded. It can be switched to each. Of course, if the PCM decoder 38 can also be used for digital data signals, the data decoder 52 is omitted,
The switch 51 may be provided on the output side of the PCM decoder 38. Five
A switch 3 squelches the video signal from the de-emphasis circuit 28. Reference numeral 54 denotes a tracking control circuit, which includes an equalizer 55 to which the tracking error signal output from the amplifier 25 is input, a loop switch 56 for a tracking servo loop, an adder 57, and a drive amplifier 58 for driving a tracking actuator (not shown). It consists of The video signal output from the de-emphasis circuit 28 is input to the sync separation circuit 59 and the vertical sync separation circuit 60, and the vertical sync signal is separated and detected. The detection signal of the vertical synchronizing signal is supplied to the jump pulse generating circuit 61 and the squelch control circuit 62. Reference numeral 63 is a memory control circuit for controlling the memory (RAM 75 in FIG. 3) of the data decoder 52. A jump command signal, a squelch command signal, and a memory control signal are each output from the microcomputer to the jump pulse generation circuit 61, the squelch control circuit 62, and the methyl control circuit 63.

(IV) Operation of reproducing apparatus The operation when the EFM signal is not a digital data signal is the same as the above-mentioned case, and therefore its explanation is omitted, and only the case where it is a digital data signal will be described. When a search command for the frame A or digital data D ₁ ′ to D ₅ ′ is issued from the microcomputer, the loop switch 56 is opened, and the search operation for the frame A or digital data D ₁ ′ to D ₅ ′ is started. At the same time, the squelch control circuit 62 opens the switch 53 to squelch the video signal. Frame A or digital data D ₁ ′ to
When D ₅ ′ is searched, the loop switch 56 is closed,
The tracking control device 54 operates and shifts to a normal reproduction operation. Of the playback signals from the amplifier 25, the EFM signal is
Via low-pass filter 35 and de-emphasis circuit 36
It is input to the EFM decoder 37 and is EFM demodulated. The EFM demodulated signal is input to the data decoder 52 via the switch 51, stored in a predetermined memory corresponding to the signal from the memory control circuit 63, and processed. On the other hand, when the storage operation of the last block D ₅ ′ of digital data is completed (FIG. 4 (g)), a jump command is issued to the jump pulse generating circuit 61. Then, the jump pulse generation circuit 61 outputs a jump pulse to the adder 57 at the timing at which the vertical sync signal is next detected by the vertical sync separation circuit 60 (of course, immediately after the reading of the last block D ₅ ′ is completed, the jump pulse is output. Need not wait until the next vertical sync signal is detected). Therefore, the tracking actuator is driven, and the pickup 23 moves between the first field A ₁ and the second field A ₂ of the frame A from the vicinity of the vertical synchronizing signal between the first field C ₁ and the second field C ₂ of the frame C. 2 tracks (2 frames) are jumped back in the vicinity of the vertical sync signal of. And the second field A ₂
After the normal reproduction, the jump pulse is generated again in the vicinity of the vertical synchronizing signal immediately after the second field A ₂ , and two tracks (2 frames) are generated in the vicinity of the vertical synchronizing signal immediately before the first field A _1. Jump back. After that, the operation of jumping back one track after reproducing the frame A is repeated to reproduce the still image of the frame A (FIG. 4 (e)). On the other hand, the squelch control circuit 62 closes the switch 53 to release the squelch when jumping back to a position near the vertical synchronizing signal immediately before the frame A for the first time. Therefore, only the still image of the frame A is observed by the user (FIG. 4 (f)). When the processing of the digital data signal is completed, this still image reproducing operation is also canceled and the operation shifts to the next operation.

FIG. 3 shows a more detailed block diagram of the EFM decoder 37 and the data decoder 52 (the switch 51 between the two is omitted). That is, in the EFM decoder 37,
The input EFM signal is waveform shaped by the waveform shaping circuit 71, and E
The signal is demodulated by the FM demodulator 72, temporarily stored in, for example, a 16-kilobit RAM 73, and after processing such as deinterleaving, an error detection / correction circuit 74 performs error detection / correction. Further, in the data decoder 52, the digital data is temporarily stored in the RAM 75, read out or the like is performed by the control signal from the memory control circuit 63, and the error detection / correction circuit 76 performs error detection / correction and outputs the data. ing. RAM75 capacity is about 3 for 2 blocks
With 8 kilobits, it is possible to capture digital data for one image at a time, but it is also possible to take about 19 kilobits for one block. Thus, when the length of the series of digital data recorded on the disc exceeds the capacity which the RAM 75 can store at one time (of course, it does not have to), the first block D ₁ ′ From the neighborhood of the vertical sync signal immediately before the last block D ₅ ′ to the neighborhood of the vertical sync signal immediately after the last block D ₅ ′, and from the neighborhood of the vertical sync signal immediately after the last block D ₅ ′ to the first block D ₁ ′. It is also possible to repeat the jumpback operation up to the vicinity of the vertical synchronization signal immediately before (regardless of the path), and after the processing of the digital data once stored is completed, store the next block in sequence and process it. it can. Meanwhile, the squelching field or frame of the video output can be arbitrarily selected. For example,
It is also possible to record the same image in the frames A, B, C, etc., and always reproduce it as a still image during the jump repeating operation. Start and end points for repeating the reproduction operation and the jump back operation also, for example 'as shown in, the first block D ₁ FIG. 4 (e)' and the vicinity of the immediately preceding vertical synchronizing signal, the last block D ₅ ' Near the vertical sync signal immediately after the frame C where the terminal end is located (solid line in the figure), or near the vertical sync signal one field before the field where the beginning of the first block D ₁ ′ is located, and the last block It can be near the vertical synchronizing signal immediately after the end of D ₅ ′ (broken line in the figure). In these cases, the reproduction operation and the operation of jumping back by 3 frames (3 tracks) are repeated.

When the length of digital data is 1 block, the length after interleaving of 1 block which is the minimum unit is shorter than 1 frame, and the beginning can jump as described above instead of the position of all vertical sync signals. By setting the position s of the vertical synchronization signal one frame (one rotation) before the position, the squelch of the video signal can be canceled at the time when the position s is searched, and the squelch time can be shortened. Also, regarding the jump position, it is possible to ensure compatibility with an already commercialized normal video disc.

〔effect〕

According to the invention of the present application, the digital data recorded in the invention of the present application is divided into blocks, and the beginning of the interleaved data is always recorded so as to substantially match the vertical synchronization signal. The length is automatically selected, and even if the frequency relationship between the television video signal and the digital data is not in a simple multiple relationship, the digital data is reliably recorded in a corresponding relationship with the television video signal. . And
When reproducing a video disc recorded according to the present invention, the squelch is canceled in accordance with the vertical synchronizing signal without shortening the squelch time without considering the frequency multiple relationship between the television video signal and the digital data. You can Further, when jumping at the time of reproduction, the squelch operation is performed substantially in accordance with the vertical synchronizing signal to perform the jump, so that compatibility with other video discs already commercialized can be ensured.

[Brief description of drawings]

1 is a block diagram of the recording apparatus of the present invention, FIG. 2 is a block diagram of the reproducing apparatus, FIG. 3 is a more detailed block diagram of a part of the reproducing apparatus, and FIG. Timing chart, Fig. 5 is a schematic plan view of a field of a television video signal, Fig. 6 is a spectrum diagram of an optical video disc, Fig. 7 is a spectrum diagram of an EFM signal, and Fig. 8 is a record of the EFM signal. FIG. 9 is a spectrum diagram of an optical video disc, and FIG. 9 is a block diagram of a conventional optical digital audio disc recording device.
The figure is a block diagram of the reproducing apparatus. 1, 4, 5, 11 ... Pre-emphasis circuit 2, 6, 7 ... FM modulator 3 ... Adder, 8 ... PCM encoder 9 ... EFM encoder 10 ... Low-pass filter 12 ... Limiter, 13 ... … Light modulator 14 …… Laser light source 15,24 …… Objective lens 17 …… Recording master, 22 …… Video disc 23 …… Pickup, 25 …… Amplifier 26,29,30 …… Band pass filter 27,31, 32 …… FM demodulator 28,33,34 …… De-emphasis circuit 37 …… EFM decoder 38 …… PCM decoder 41 …… Memory, 42 …… Position detection means 51,53 …… Switch 52 …… Data decoder 54… … Tracking control circuit 61 …… Jump pulse generation circuit 73, 75 …… RAM

Claims (2)

[Claims] 1. A video disc recording method for frequency-dividing a television video signal and digital data into multiple recording on the same track, wherein the position of a vertical synchronizing signal contained in the television video signal is detected and recorded. The digital data to be recorded is divided into blocks, a block group is formed by the divided one or a plurality of blocks, and interleave is performed for each of the formed block groups to generate interleaved data to be recorded, and the generation is performed. When sequentially recording the interleaved data,
By making the beginning of the interleaved data to be recorded next substantially coincident with the timing of the vertical synchronizing signal detected after the last recording timing of the previous interleaved data,
A video disk recording method, characterized in that the interleaved data is recorded in the track together with the television video signal. 2. A video disc recording apparatus for frequency-dividing a television video signal and digital data and recording the same on the same track in a video disc recording apparatus, and position detecting means for detecting the position of a vertical synchronizing signal included in the television video signal. Recording means for interleaving the transferred block group data and recording the interleaved interleaved data on the track together with the television video signal, storing the digital data, and dividing the stored digital data into blocks. , The divided block or blocks constitutes the block group, and substantially coincides with the timing of the vertical synchronizing signal detected after the last recording timing of the interleaved data recorded by the recording means last time. Of the block group to be interleaved next The chromatography data video disk recording apparatus characterized by comprising a memory for output to the recording means.