JPS60198987A - Video disc record - Google Patents

Abstract

PURPOSE:To reproduce stably a sound signal by recording a digital sound signal subject to time axis compression during the vertical blanking period of a broad band video signal. CONSTITUTION:The sound signal on channels A1, A2 is inputted to an AD conversion circuit 5, its output is inputted to a coding circuit 6, where the signal is subject to quasi-instantaneous companding and interleaving, and then converted into a data added with a correction data such as error correction code at each data unit. Then the data is stored sequentially to a memory 7 according to an output of a write address designation circuit 8. The output of the memory 7 is inputted to a multiplex circuit 12 together with the output of an address signal generating circuit 10 and the output of a track jump signal generating circuit 11. In case of multiplexing of a signal in, e.g., 456 bits per line, the front 5 bits and the rear 7 bits of the horizontal synchronizing signal are used as free areas so as to part the sound digital signal fluctuated rapidly from the horizontal synchronizing signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a video disc record for recording high quality video signals and audio numbers.

(b) Conventional technology high-definition video signals have a luminance signal band of 20 MHz and 7 MHz.
In order to directly FM-modulate the high-definition video signal No. z and record it on a video disc record, the video disc record must be rotated at a high speed faster than the field period. The possible time is limited to less than half of that of conventional video disc records, making it unsuitable for practical use.

Therefore, it is possible to band-compress the high-quality video signal. An example of a band compression transmission method is the TCI multiple sub-sampling method. This transmission method is proposed by the Japan Broadcasting Corporation as an example of a satellite broadcasting method. This method compresses the time axis of the color signal band to 174 and uses it in the horizontal blanking period, as shown in the Technical Report of the Television Society of Japan, TEBS91-5 dated October 20, 1988. The TCI transmission method that multiplexes the signal and shifts the phase of this multiplexed signal by 90' in the field period.
It combines a multiple subsample transmission method in which different sampling points are sampled for each field using a 2MHz sampling pulse, and the transmission band is 8.1Mz as a result of band compression.

When recording a video signal of 8.1 MHz obtained by the above-mentioned transmission method by FM modulation, it is possible to record the video signal by rotating a high-speed disc record at a field period.

However, when recording a broadband video signal on a video disc record instead of a high-quality video signal, the problem of audio signal recording remains. Conventional video recording codes record the audio signal by FM modulating it in a lower band than the FM modulation band of the wideband video signal and multiplexing it, but since it is an analog signal, dropout compensation is not possible. This necessitated the use of difficult scales and a circuit to prevent beat interference from the video.

(c) Purpose of the Invention In view of the above points, the present invention provides B1. This paper proposes a video 5'-isf record that realizes multiplexing of audio signals without worrying about interference and with less influence of dropouts.

(d) Structure of the Invention The present invention is characterized in that an audio signal is converted into PCM and is compressed and multiplexed into 8-column format during the vertical blanking period of a wideband video signal.

(e) Examples Hereinafter, the present invention will be explained according to an illustrative embodiment.

FIG. 1 shows a block diagram of a signal recording circuit in which the present invention is applied to a video disc record.

First, a high-quality video signal is input to the TCI encoder (1) in the form of three primary color signals of R, G, and B. This encoder (1) converts the color signal into a line sequential signal, compresses the time axis to 174, and multiplexes it four lines ahead of the horizontal blanking period of the combined luminance signal.

This multiple fi signal is input to a subsample filter (2), and multiple subsamples are generated using a 16.2 MHz sampling pulse. In other words, the 16.2 MHz sampling pulse is repeated by repeating sampling while allowing the signal phase to shift by 90' for each field.
By alternating the positions, the sampling point change period is set to four fields.

The signal obtained by the above-mentioned multiple sub-samples requires a signal that compensates for the temporal movement of the screen when synthesizing the screen because one screen of a moving image is formed by four consecutive fields. Therefore, a 32-bit control signal (CNI) (C
N2) and each section of the screen (32 horizontally x 16 vertically)
A block control signal (s
cl) (, Bc2) and the control signal generation circuit (
3) and the block control signal generation circuit (4).

FIG. 2 is an explanatory diagram showing the temporal order of these signals. This wideband video signal consists of 1125 lines per frame, and the number of rimbling points per line is 480 points.In one line, the first 2 points are horizontal synchronization signals, and the following 94 points are color signals. Luminance signals are multiplexed at the remaining 374 points. In addition, each field has 519 luminance signal lines, and in both fields, the block detection signal IBc1) (BO2) of the corresponding field is multiplexed on the four lines preceding the luminance signal (Yl) (Y2), and the color signal The control signal (CNI) (CN2) of the subsequent field is multiplexed onto the five lines connected to (C1) and (C2).

Furthermore, the final line of the hunt roll signal (CNI) (CN2) includes a luminance clamp level signal (MCI) (YC2).
are multiplexed. Further, on the two lines preceding the color signal (C2) on the even field side, a frame synchronization signal (F
L) can be multiplexed.

Therefore, the blanking period on the odd field side (BLI
) is 38 lines extending from the 6th line to the 43rd line, the blanking period (BL2) on the even field side is 37 lines extending from the 568th line to the 604th line, and the odd field is 468 (=94+374)X
38bjj”17784bit and even field is 4
Digital signals of 68×37 bits=17316 bits can be multiplexed.

In this embodiment, audio information is multiplexed in each vertical blanking period. The audio signal of the 2-channel (AI) (A2>) is first input to the AD conversion circuit (5). AD conversion frequency is 32KH2 and conversion bits are 14 bits
It is. This 14-bit data is first processed by the encoding circuit (
6) is input to 10 bits of data, quasi-instantaneous companding is performed, and then interleaved and correction data such as an error correction code is added to every 640 bits of data (2X 32X 10) in units of 1m5ec, resulting in 1024 bits. 1
The data is converted into blocks. This data is a signal obtained by removing the 3rd and 4th channel data from the A mode signal of the Radio Technology Council and adding a predetermined high 8 minutes 0.
Memo 1 sequentially according to the output of the write address designation circuit (8)
buff).

The feature of this embodiment lies in the method of multiplexing this audio data. That is, the data that can be multiplexed during the vertical blanking period of both fields is a maximum of 173 blocks and 169 blocks, and it is sufficient to multiplex 333 blocks per frame. Therefore, the multiplexing method is 37 lines and 36 lines. If you multiplex the data into 1 line, and then multiplex the control signal of Tora 7 Kuno A/Nbu identification (No. 8, etc.) onto each remaining line,
Data can be multiplexed efficiently.

However, in order to perform the above-mentioned multiplexing, the audio data must be multiplexed close to the horizontal synchronization signal. However, in the case of a wideband video signal, the horizontal synchronization signal changes within the range of the video signal level as shown in FIG.
In 2), the level change is reversed between the second point and the eleventh point, and the synchronization timing is set at the sixth point, that is, the midpoint of the level change. Therefore, compared to conventional video signals, the timing of synchronization separation tends to fluctuate depending on the level of adjacent signals. Therefore, in the case of such a tJ wideband video signal, the digital signal with sharp level changes is multiplexed close to the horizontal synchronization signal. Nails are undesirable;
It is better to suppress level fluctuations as much as possible before and after the horizontal synchronization signal, as shown by the dotted line. It is assumed that the levels of the first point and the i12 point indicated by the X marks are set to the midpoint between the preceding and following signal levels.

Therefore, in this embodiment, in order to multiplex the audio data as far away as possible from the horizontal synchronization (+\) signal, the audio data to be multiplexed per each vertical blanking period is multiplexed equally on each twin.

That is, in this embodiment, 456-bit signals are multiplexed per line. Furthermore, in this embodiment, when multiplexing 456b ports as shown in FIG.
The 7 bits after the bit are used as gray-level empty corriers, and in particular, by providing a 5-focus empty area in advance of the horizontal synchronizing signal, the shift in the timing of synchronizing pulse generation during reproduction can be completely eliminated.

In this embodiment, as described in F, since audio data is multiplexed over the entire vertical blanking period of one blank space, there is no position for multiplexing track diagonal identification signals and address signals for still image playback. .

Therefore, in this embodiment, the brightness signal of the final twin and the tiger/shoe/embu identification signal (SJ) are permuted and multiplexed, and the color signal and address signal (ADI) of the final line are multiplexed by substitution.
AC3) are permutation multiplexed.

In addition, if the Tora/Kunhe Mbu identification signal (SJ) is turned on,
By multiplexing two lines in front of the audio data, a 7--\-amp is performed during the audio data playback period, and the playback screen is prevented from being disturbed during special playback.

Furthermore, the address signal (ADI) (AC3
) can be replaced with the final color information, which is relatively harmless even if removed, and only the color component of the final line is removed.

An address signal generation circuit (10), a trunk identification signal generation circuit (11), a control signal generation circuit (3), a subsample filter (2), a block control signal generation circuit (4), and a memory. Each output (7>) is input to a multiplexing circuit (12), and a multiplexed signal as shown in FIG. 4 is derived.

This multiplexed signal is input to the FM modulation circuit (13) and the FM
By operating the modulation output or optical modulation means, the recording beam is modulated to form a spiral recording track on a disk record that rotates at a frame period of 4''.

FIG. 5 is a diagram schematically showing a video area (V) and an audio area (A) of a video disc record (DR).

The optical recording mechanism of the video disc record is a well-known structure, and illustrations and detailed explanations will be omitted.

The above-mentioned video disc player that plays back video disc records inputs FM-modulated wideband video signals and audio data to a band compression decoder installed in a high-definition television receiver. The video output that has been converted to video No. 18 and the audio output that has been converted to an analog signal can be input to a high-definition television receiver.

(f) Effects of the Invention According to the present invention, since the audio signal is multiplied as a PCM signal during the vertical blanking period, the audio signal can be stably reproduced, and the effect is great.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 shows a signal recording circuit according to an embodiment of the present invention.
Figure 2 is an explanatory diagram of the signal distribution for one frame of the broadband video signal of this embodiment, Figure 3 is an explanatory diagram of the waveform of horizontal synchronization No. 18, and Figure 4 is an illustration of one frame recorded on a video disc record. FIG. 5 shows an explanatory diagram showing the signal area distribution of a video disc record. Explanation of main figure numbers: (OR), disk record, (BL), vertical blanking period, (PCM), audio data. Applicant Sanyo Electric Co., Ltd. Agent Patent Attorney Shizuo SanoSa Diagram ■ Figure 5

Claims (2)

[Claims] (1) Time axis compression of the color signal of high-quality video signal
A wideband video signal that is multiplexed in the horizontal blanking period preceding the 1 degree signal and band-compressed by a multiple subcombination method, and a digital audio signal that is time-base compressed in the vertical blanking period of the wideband video signal are recorded. video disc record. (2) The video disc record according to claim 1, wherein the digital audio signal is recorded using FM modulation.