JPS61288580A - Sound signal recording and reproducing system with still picture - Google Patents

Abstract

PURPOSE:To improve the recording density and to increase the recording quantity remarkably by recording a still picture signal by one picture in a constant angular velocity onto one integral number of sriral tracks on a disc recording medium and recording a sound signal in a constant line velocity on a prescribed section ahead the spiral track. CONSTITUTION:The sound signal is recorded in a constant line velocity on sound signal recording blocks A1, A2- on a disc, while a still picture signal is recorded in a constant angular velocity on still picture signal recording blocks V1, V2 ... so as to record the still picture signal of 1 frame onto the track of one revolution of the disc. The sound signal subject to time axis compression is recorded on sound signal recording blocks A1, A2 ... and the sound signal on the block A1 on the disc is reproduced and written in a memory at reproduction, the sound signal is read from the memory while applying time axis expansion in a prescribed speed and the block V1 on the disc is reproduced at the same time while track jump is applied at one revolution to apply still picture reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for recording and reproducing a still image video signal and an audio signal on a video disc. [Background of the Invention] Conventional Art A still image-accompanied audio recording and reproducing method is known in which a still image signal and an accompanying audio signal are recorded on a video disc, and these are played back so that the still image can be viewed while listening to music or explanations. ing. An example of such prior art is, for example, Japanese Patent Application Laid-Open No. 54-2771.
As described in Publication No. 9, a time-axis compressed audio signal is recorded in one to several rotation sections of a video disk rotating at a constant angular velocity, and a still image signal is recorded in the following one to several rotation sections, and when playing back, first , the audio signal is reproduced and stored in the memory, and then the video signal is repeatedly reproduced while the still image is reproduced, and at the same time, the audio signal is read out from the memory with time axis expansion. However, in such conventional technology,
No consideration was given to the recording efficiency of video discs, especially to improving the recording density of audio signals.

[Purpose of the invention]

An object of the present invention is to eliminate the drawbacks of the above-mentioned conventional techniques, improve the recording efficiency of a disk-shaped recording medium, and record and reproduce still image signals and audio signals accompanying the still image signals. Our goal is to provide the following.

[Summary of the invention]

In order to achieve this object, the present invention records a still image signal for one image at a constant angular velocity for one or an integral number of revolutions of a spiral track of a disk-shaped recording medium, and repeatedly reproduces this signal at a constant angular velocity. The present invention is characterized in that a still image can be obtained and an audio signal is recorded at a constant linear velocity in a predetermined section preceding the recording section of the still image signal.

On a video disc, one frame of still image signal is recorded in one revolution of a spiral track, and while this is rotated at a constant angular velocity, a track jump is performed to start playback from the recording start position of the still image signal every revolution. It is known that still images can be played back. On the other hand, it is also known that, for example, if signals are recorded on a disk at a constant linear velocity, such as a compact disk, the recording efficiency of the disk increases and the recording density of the disk increases. In a system that records still image signals and accompanying audio signals on a video disc and plays them back, a section for time-base compression recording of the audio signal is provided prior to the section for recording the still image signal, and during playback, first, The audio signal is read from the disk and stored in the memory, and when the playback of the still image signal starts, the audio signal is expanded on the time axis and read from the memory, and the still image signal is repeatedly played back by performing a track jump every time the disk is played. This allows a still image and accompanying audio to be obtained. In this way, in order to play back the still image signal in real time, it is necessary to record it at a constant angular velocity, but the played audio signal is partially stored in memory and then read from this memory.
Recording can be performed using a constant linear velocity method with good recording efficiency, improving the recording density of the disc. In this case, during playback, the rotation speed is changed by switching the disc drive from constant linear velocity to constant angular velocity in the audio recording section and image recording section. However, since the time to reproduce the still image is longer than the time to read the audio portion, the time loss associated with switching the rotation speed is not a problem. Furthermore, even if the signal reading speed changes, it is possible to configure the audio signal reproducing circuit to follow the signal reading speed, write it to the memory, read it out at a constant speed, and play it back.In this way, the angular velocity of the disk is constant. It can be played by rotating.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a spiral track formed on a video disk for explaining an embodiment of the still image-attached audio signal recording and reproducing method according to the present invention.
Vl-Va represents a track portion where an audio signal is recorded (hereinafter referred to as an audio signal recording section), and Vl-Va represents a track portion where a still image signal is recorded (hereinafter referred to as a still image signal recording section).

In FIG. 1, all audio signal recording sections on the disk
In A21 As, A4, . . . , the audio signal is recorded at a constant linear velocity, and if the audio signal playback time for each is equal, the length of each audio signal recording section is equal. On the other hand, the still image signal recording section Vl + V2 *
In V3, V4, etc., still image signals are recorded at a constant angular velocity, and in this embodiment, one frame of still image signals is recorded so as to fit into a track portion of one rotation of the disk.

During playback, a track jump is performed once per revolution of the disc, making it possible to easily play back still images. Audio signal recording section AI + A2 + A
A time-axis compressed audio signal is recorded in s r A4 .
The audio signal is read out from this memory while expanding the time axis at a predetermined speed, and at the same time, a still image is reproduced by repeatedly reproducing section vl on the disk while performing track jumps every rotation.

If the still image signal is recorded with FM modulation in the same way as a normal video disc, the playback circuit of a conventional video disc can be used in common. On the other hand, audio signals can be time-base compressed and FM modulated recorded while remaining analog signals; in this case, the memory used for time-base compression is COD.
There are analog memories such as 1, and analog audio signals played from the disk may be partially A/D converted and stored as digital signals, and D/A converted when read out. It is also possible to record it on a disc as a digital signal. In this case, by performing FM modulation and recording in the same way as the still image signal so that the bit rate of the time-axis compressed digital audio signal matches the frequency band of the still image signal, the playback circuit up to the FM demodulator can reproduce the still image. Can be used for both signals and audio signals. Also, the audio signal can be converted to MFM.

It may also be converted into a run length limited code such as EFM and directly digitally recorded.

As described above, in the embodiment, the audio signal uses the constant linear velocity force type, which is advantageous in terms of recording density, and the still image signal uses the constant angular velocity force type, which is advantageous for still image reproduction. and the accompanying audio signals can be efficiently recorded on a disk.

Figure wJ2 shows another embodiment of the still image-attached audio signal recording and reproducing method according to the present invention, in which (a) is a schematic diagram showing the signal recorded on the disk, and (b) is a schematic diagram showing the signal recorded on the disk. FIG. 3 is a schematic diagram showing tracks formed on a disk. Second
In figure (a), A is an audio signal, ■ is a still image signal,
3 is an identification code signal, C is an audio signal end signal, and E is a still image signal end signal. Further, in FIG. 2(b), Al indicates an audio signal recording section, and V+ indicates a still image recording section.

(2) is an identification code signal recording section + CI is an audio signal end signal recording section, and El is a still image signal end signal recording section.

In this embodiment, signals representing the start and end of the audio signal recording section and signals representing the end of the still image signal recording section are also recorded, making it easier to reproduce still images and audio.

In FIG. 2, an audio signal A and a still image signal V are the same as those in the embodiment shown in FIG. The identification code signal engineer is the identification code signal recording section 1 preceding the audio signal recording section A1.
1, and is a signal indicating the identification of each still image audio signal and the start of the audio signal recording section AI. It is added corresponding to each still screen, and is added to the beginning of the still image from the beginning of the disc, for example. serial number, etc. In addition, when the audio signal A is a digital audio signal, the identification code signal I such as this serial number is such that the signal with the same code is the same as that of the audio signal A.
In order to prevent bit patterns appearing in the audio signal A from being mistakenly taken as identification code signals, bit patterns that appear in the audio signal A with little certainty are added before, after, or on both sides of the necessary identification code signal, and these bits are The pattern and the necessary identification code may be included as an identification code signal (■). The audio signal end signal C is recorded in the audio signal end signal recording section C1 between the audio signal recording section A1 and the still image signal recording section v1, and is a signal indicating the end of the audio signal recording section Al. It is sufficient to select a bit pattern that is unlikely to appear in the audio signal and use it as the audio signal end signal. The still image signal end signal E is recorded in the still image signal end signal recording section E1 following the still image signal recording section V1, and indicates the end of the still image signal recording section v1 for one frame. By detecting this, a one-track track jump is performed to facilitate still image playback.

Among these signals, the identification code signal■.

The audio signal A and the audio signal end signal C are recorded at a constant linear velocity, and the still image signal V and the image signal end signal E are recorded at a constant angular velocity. This allows a smooth connection from the detection of the identification code signal to the reproduction of the audio signal A, and
The audio signal end signal C can also be reliably detected.

FIG. 6 is a block diagram showing a specific example of the still image-attached audio signal reproducing apparatus according to the first embodiment, in which 1 indicates a disk;
2 is a disk drive motor, 3 is an optical pickup, 4 is
1 is a motor drive circuit, 5 is a disk rotation control circuit, 6 is a control signal detection circuit, 7 is an audio signal demodulation circuit, 8 is a video signal reproduction circuit, 9 is a pickup skip control circuit, 10 is an operation switch, 11 is a memory, 12 is an audio signal reproduction circuit,
13 is an image signal output terminal, and 14 is an audio signal output terminal.

In the figure, when a desired still image is selected to be reproduced by the operation switch 10, a selection code corresponding to the identification code of the desired still image is output to the operation switch iou control signal detection circuit 6, and at the same time, A rotation start signal is output to the disk rotation control circuit 5. When the disk rotation control circuit 5 receives the rotation start signal, it outputs a control signal for driving the motor drive circuit 4 at a constant linear velocity. The motor drive circuit 4 rotates the disk drive motor 2 based on this control signal, and drives the disk 1 at a constant linear velocity.The optical pickup 3 reproduces a signal from the rotating disk 1, and the reproduced signal is based on the control signal. Detection circuit 6. Audio signal demodulation circuit 7 and video signal reproduction circuit 8
is input. The control signal detection circuit 6 detects the identification code signal from the reproduced signal from the optical big ag 3, and if this matches the selection code from the operation switch 10,
An audio demodulation start signal is sent to the audio signal demodulation circuit 7. Then, the audio signal demodulation circuit 7 demodulates the time-base compressed audio signal A reproduced from the optical loudspeaker 3 and writes this demodulated audio signal into the memory 11.

When the reading of the audio signal recording section Al is completed in this way, the control signal detection circuit 6 detects the audio signal end signal C, and sends a rotation switching signal to the disk rotation control circuit 5 and an audio signal to the audio signal demodulation circuit 7. A demodulation end signal is supplied to the video signal reproduction circuit 8, a video reproduction start signal is supplied to the audio signal reproduction circuit 12, and an audio reproduction start signal is supplied to the audio signal reproduction circuit 12.

As a result, the audio signal demodulation circuit 7 writes the audio signal end signal into the memory and stops the demodulation operation.

Further, the disk rotation control circuit 5 outputs a control signal for driving the motor drive circuit 4 at a constant angular velocity, so that the one-disk drive motor 2 drives the disk 1 at a constant angular velocity.

The video signal reproducing circuit 8 starts processing the still image signal A reproduced from the optical pickup 3 and outputs it to the image signal output terminal 13. At the same time, the audio signal reproducing circuit 12 starts reading out the audio signal which has been time-extended at a predetermined speed from the memory 11 and supplies it to the audio signal output terminal 14 after performing predetermined processing. When the control signal detection circuit 6 detects the image signal end signal E during still image signal reproduction, it sends a detection signal to the video signal reproduction circuit 8. If the still image signal is being reproduced at this time, the video signal reproduction circuit 8 sends a jump control signal to the jump control circuit 9. Upon receiving this skip control signal, the skip control circuit 9 returns the reading position of the optical pickup 3 by a predetermined number of tracks (one track in the embodiments shown in FIGS. 1 and 2), and returns the still image signal to Reproduction is repeated from the beginning of section Vl.

In this way, the still image signal is reproduced and outputted from the image signal output terminal 15, and the audio signal associated therewith is reproduced and outputted from the audio signal output terminal 14, respectively.

When the audio signal reproducing circuit 12 finishes reading out all the audio signals from the memory 11, the audio signal end signal C is finally read out from the memory 11, and when the audio signal reproducing circuit 12 detects this, it outputs the reproduction signal to the operation switch 10. At the same time as sending the end signal, the playback of the audio signal is stopped, and the operation switch 10 is pressed.
sends a stop signal to the video signal reproducing circuit 8 and the disk rotation control circuit 5, stopping disk reproduction and ending still image signal output.

FIG. 4 is a block diagram showing another specific example of the still image-attached audio signal reproducing device, in which 4' is a motor drive circuit that causes the disc drive motor 2 to rotate the disc 1 at a constant angular velocity, and 6' is a motor drive circuit that allows the disc drive motor 2 to rotate the disc 1 at a constant angular velocity. Identification code signal I and audio signal end signal C
7' is an audio signal demodulation circuit that operates according to an external clock; 8' is a video signal reproducing circuit having a function of detecting a still image signal end signal E; 15
is a PLL (phase locked loop circuit) for obtaining a clock synchronized with the optical pickup output signal, and the third
Parts corresponding to the figures are given the same reference numerals. In this specific example, it is assumed that the audio signal, identification code signal, and audio signal end signal are directly recorded digitally.

In FIG. 4, when a desired still image is selected for reproduction by the operation switch 10, the operation switch 10 sends a selection code to the control signal detection circuit 6', similar to the specific example shown in FIG. Output. At the same time, a rotation start signal is sent to the motor drive circuit 4', which causes the motor drive circuit 4' to rotate the disk drive motor 2 and drive the disk 1 at a constant angular velocity.

The optical pickup 3 reproduces a signal from the rotating disk 1, and the reproduced signal is transmitted to a control signal detection circuit 6', an audio signal demodulation circuit 7', a video signal reproduction circuit 8' and a PLL 1.
5. The control signal detection circuit 6' detects the identification code signal I from the reproduction signal of the optical pickup 3, and if this matches the selection code from the operation switch 10,
An audio demodulation start signal is sent to the audio signal demodulation circuit 7'. The audio signal demodulation circuit 7' converts the digital audio signal, which is reproduced by the optical pickup 3 and compressed in the time axis and whose transmission rate gradually changes, to the transmission rate using a clock from the PLL 15 synchronized with this reproduced signal. The digital audio signal is then demodulated and written into the memory 11.

When the control signal detection circuit 6' detects the audio signal end signal E, the audio signal demodulation circuit 7' receives an audio demodulation end signal, the video signal reproduction circuit 8' receives a video reproduction start signal, and
An audio reproduction start signal is supplied to each of the audio signal reproduction circuits 12. As a result, the video signal reproducing circuit 8' causes the optical pickup 3 to start reproducing the still image signal V, and outputs it to the still image signal output terminal 15. At the same time, the audio signal reproducing circuit 12, similar to the specific example shown in FIG.
The time-axis expanded audio signal is output to the audio signal output terminal 14.

When the video signal reproducing circuit B detects the image signal end signal E during the reproduction of the still image signal V, the video signal reproducing circuit B sends an interlacing control signal to the interlacing control circuit 9. As a result, the jump control circuit 9 controls the optical pickup in the same manner as in the specific example shown in FIG.
Trace 1 repeatedly. In this way, the still image signal is transmitted from the still image signal output terminal 13 to the audio signal output terminal 14.
The audio signals accompanying them are respectively reproduced and output.

When all the audio signals stored in the memory 11 are read out, the audio signal reproducing circuit 12 sends a stop signal to the video signal reproducing circuit 8' and the motor drive circuit 4' via the operation switch 10, and ends the reproduction of the disc. .

Note that in this embodiment, the audio signal is MFM.

Although we have explained the case where the audio signal is directly recorded digitally using FM modulation, if the audio signal is recorded using FM modulation, the audio demodulation circuit 7' may be a PLL demodulation system, for example.
The configuration may include any wideband FM demodulation circuit so as to be able to follow changes in the playback speed of the playback signal from the disc 1.

FIG. 5 is a block diagram showing a specific example of a still image-attached audio signal and recording device for the embodiment shown in FIGS. 1 and 2, in which 16 is a video signal input terminal and 17 is an audio signal input terminal. Input terminal, 18 is a video signal modulation circuit, 19 is an audio signal modulation circuit, 20 is a memory, 21 is an audio signal processing circuit,
22 is a VCO (voltage controlled oscillator), 23 is a signal switching circuit, 24 is a control circuit, 25 is a laser light source, 26 is a laser modulator, 27 is a disk drive motor, and 28 is a disk master. - A still image signal obtained from an image generator (not shown) such as a spot scanner is input from the video signal input terminal 16, and after a synchronization signal is added by the video signal modulation circuit 18, it is FM modulated. The signal is supplied to the signal switching circuit 23. On the other hand, the audio signal is supplied from the audio signal input terminal 17 to the audio signal processing circuit 21,
The data is sampled at predetermined time intervals and written to the memory 20. When the data has been stored in the memory 20, the control circuit 24 switches the signal switching circuit 23 to the audio signal side and activates the audio signal modulation circuit 19.

The disk drive motor 27 rotates at a constant rotation speed, and the disk master 28 is rotationally driven at a constant angular velocity. A control voltage corresponding to the radial position of the disk is applied to the VCO 22.

The audio signal modulation circuit 19 reads the audio signal from the memory 20 at a speed proportional to the output frequency of the VCO 22, thereby obtaining the audio signal A compressed in the time axis. This audio signal A is passed through the signal switching circuit 23 to the laser modulator 26.
The laser beam is modulated to expose the photoresist on the surface of the disk master 28, thereby recording an audio signal. At this time,
The transmission speed of the audio signal A is controlled by the VCO 22, and is recorded at a constant linear velocity on the disk.0 When all the audio signals have been read out from the memory 20 and the recording has been completed, the control circuit 24 transfers the signal The switching circuit 23 is switched to the still image signal side, and the FM-modulated one-frame still image signal V modulates the laser beam in the laser modulator 26, which is irradiated onto the disk master 28 to generate the still image signal V.
will be recorded. The transmission speed of the still image signal is constant, and it is recorded at a constant angular velocity of one frame per rotation of the disk. At the beginning and end of both the audio and still image signals, the control circuit 24 inserts an identification code signal, an audio signal end signal C9, an image signal end signal E, respectively, via the signal switching circuit 23. In each specific example, the case where an optical video disk is used has been explained, but it goes without saying that the present invention can also be applied to other disk-shaped recording media such as a capacitance type video disk. It goes without saying that the specific example shown in FIG. 4 can be used even when both audio and still image signals are recorded at a constant angular velocity.

In the present invention, if the recording position of the horizontal synchronization signal of the still image signal is shifted between adjacent tracks and crosstalk occurs between the adjacent tracks, the image quality of the reproduced still image deteriorates. As a countermeasure, increase the length of the audio signal section by 1
It is effective to adjust the length of the horizontal section during recording to match the recording position of the horizontal synchronization signal of the still image signal between adjacent tracks. A concrete example of such a track pattern is shown in FIG. In the figure, A1. A2V1. V2. I
1, E1+Cl's symbols 1ti'$1.2 correspond to the #'s in the diagram, and TIT T21 Ts each indicate adjacent tracks on the disk. Moreover, the broken line indicates the recording position of the horizontal synchronization signal.

〔Effect of the invention〕

As explained above, according to the present invention, image signals are recorded using a constant angular velocity method that is advantageous for still image reproduction, and audio signals are recorded using a constant linear velocity method that is advantageous in terms of recording density. An excellent effect can be obtained in that the recording density of the recording medium is improved and the amount of recorded audio signals with still images per disk-shaped recording medium can be significantly increased.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams showing embodiments of the still image-attached audio signal recording and reproducing system according to the present invention, and FIGS. 3 and 4 are specific diagrams of the still image-attached audio signal reproducing apparatus according to these embodiments, respectively. A block diagram showing an example; FIG. 5 is a block diagram showing a specific example of the still image-attached audio signal recording device for the above embodiment; FIG. 6 is a specific example of the track pattern in FIGS. 1 and 2. FIG. 1...Disk 2...Disk drive motor 5...
・Disk rotation control circuit 6...Control signal detection circuit
7.7'...Audio signal demodulation circuit 8.8'...Video signal reproduction circuit 9...Jump control circuit 15...PL
L Pay 1 figure A3 Start 2 figure

Claims (1)

[Claims] In the still image-attached audio signal recording and reproducing method, a still image signal is recorded on a spiral track of a disk-shaped recording medium, and an audio signal is recorded in a predetermined section preceding the recording section of the still image signal. The still image signal is characterized in that a video signal for an integral number of frames is recorded and reproduced at a constant angular velocity for each integral number of tracks of the disc-shaped recording medium, and the audio signal is recorded and reproduced at a constant linear velocity in the predetermined section. Audio signal recording and playback method with still images.