JPS61273083A - Method for recording and reproducing audio signal with still picture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for recording and reproducing an audio signal with still images, and in particular, a method for recording and reproducing a still image video signal and an audio signal on a video disk and reproducing both signals simultaneously. The present invention relates to a device suitable for

[Background of the invention]

A conventional device for storing a still image video signal and an audio signal for explaining the still image signal on a video disc and simultaneously reproducing these signals has conventionally been disclosed in, for example, Japanese Patent Application Laid-Open No. 54-2771.
As described in Japanese Patent Application No. 9, it is known that an audio signal of about 10 to 15 seconds is time-base compressed and recorded prior to a still image video signal. In this conventional technology, first, the audio signal is read from the video disc and stored in the internal memory of the playback system, and then, while the still image video signal is repeatedly played back from the video disc, the audio signal stored in the internal memory is simultaneously read over time. It was designed to regenerate by elongating its axis.

Here, the capacity required for the internal memory of the playback system in this conventional technique will be roughly estimated. First, the recordable bandwidth of a video disc is determined by the wavelength spot diameter of the laser beam and the linear velocity of the disc, and is approximately 13 M)lz even at the innermost circumference.

The digital signal that can be recorded within this bandwidth is about 20
Mbps is 20 Mbps, and if the rotation speed of the video disk is 50 rps, one rotation of the video disk is 20 Mbps.
This means that digital data of s X 33m5eo#6S Okbitg can be recorded. On the other hand, the audio signal is
Assuming that the signal bandwidth is 5 kHz, a sampling frequency of 10 kHz is sufficient, and if analog and digital compression/expansion techniques are used, 6 bits is sufficient for an audio signal; The transmission rate of 6-bit data is 6 okbps. The amount of data when a 10 second audio signal is converted into a digital signal at the above transmission rate is calculated as follows.

60kbpsX10sec=600kbitg
, Dook bits of digital data can reproduce approximately 10 seconds of audio signal. From the above estimation, an internal memory for storing approximately 10 seconds of audio signals requires a digital memory with a capacity of approximately 600 bits. It is often difficult to incorporate such a huge capacity of internal memory into a home-use audio playback device with still images, etc. due to cost and other factors.

An example of a device that can record and play back still images and audio signals simultaneously by reducing the capacity of the internal memory is
As described in No. 4-70721, a video signal and an audio signal are alternately recorded on a video disk for one horizontal period of the video signal, and during playback, the video signal is output as an image every -horizontal period, and the audio signal is In a horizontal period in which a video signal is missing due to recording, the video signal from the previous horizontal period is delayed and interpolated using a delay circuit, and the reproduced audio signal internally contains data of approximately 655 μBeQ within one horizontal period. A method has been proposed in which the information is stored in memory and then read out. With this conventional technology, the previous Japanese Patent Application Laid-Open No.
Compared to the internal memory in the prior art disclosed in No. 19, the bit capacity is 1/525th that of the internal memory. However, on the other hand, since the audio signal is recorded on the video disk for each horizontal period, it is necessary to interpolate each horizontal period with the signal of the previous video signal's horizontal period), and the resolution of the still image deteriorates. There was a problem.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for recording and reproducing audio signals with still images, which eliminates the problems of the prior art described above, requires less internal memory capacity in the reproducing system, and causes less deterioration in the resolution of still images. be.

[Summary of the invention]

To achieve this objective, the present invention records an audio signal on a track before or after a recording track of a still image video signal, and reads both the video signal and audio signal tracks simultaneously during playback. By repeatedly tracing the audio signal and storing it in the internal memory, the required part of the audio signal that is played every one to several revolutions is extracted and stored in the internal memory, and the period when the video signal track is being traced is The feature is that all still images are reproduced to reduce deterioration in still image resolution.

[Embodiments of the invention]

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

FIG. 1 is a block diagram showing an embodiment of the method for recording and reproducing audio signals with still images according to the present invention, in which 1 is a disk, 2 is a motor, 3 is a lens, 4 is a signal reading device, 5 is an amplifier, 6 is a video signal demodulator, 7 is an audio signal demodulator, 8 is a control code detector, 9 is a control circuit, 10
．． 15 is a changeover switch, 11.12 is a memory, 14 is an audio signal processing circuit, 15.16 is a cutoff circuit, 17 is a video output terminal, and 18 is an audio output terminal.

In the same figure, the disk 1 is moved by the motor 2 to about s o
It is rotated at a constant rotation of rpg (frame frequency of the video signal). The signal reading device 4 focuses a laser beam on the disk 1 with a lens 3, reads information on the disk, amplifies it with an amplifier 5, and applies it to a video signal demodulator 6. On the other hand, the output of the amplifier 5 is transmitted to the audio signal demodulator 7.
is applied to the control code detector 8, and the output of the control code detector 8 and the operation of the control circuit 9 repeat the track on the disk 1 in which the video signal of the same still image and the audio signal related to the still image are recorded. As shown in FIG. When using the memory 11, 11, 12, etc.
The signal stored in the audio signal is obtained from the audio output terminal 18 via the changeover switch 13, the audio signal processing circuit 14, and the cutoff circuit 16. The video signal is obtained from the output of the video signal demodulator 6 via the cutoff circuit 15 to the video signal output terminal 17.

Here, regarding the operation of the changeover switch 10.15, memory 11.12 and cutoff circuit 15.16, FIG. 2 shows the track pattern on the disk and FIG. 3 schematically shows the signals recorded on the disk. I will explain using In addition,
In FIG. 2, 19 is a disk, 20 is a disk 19
The spiral track recorded above is shown, and the period required for one rotation of the disk 19 is equal to the period of one frame of the video signal, and this will also be referred to as 17 frames.

FIG. 3 shows the signals recorded on the track 20 on this disk 19, where 21 is a video signal recorded in one frame, and 22.25 is a combination of a video signal and an audio signal related to the video signal. Control codes 24 to 29 indicate the before and after recorded audio signals, and 30 to 56 are control codes added for reading the audio signals divided into blocks. In Figure 3, a 10 second audio signal is compressed on the time axis from A to A.
, divided into blocks of 5 degrees, and one frame is about 33 m.
5e.

It is assumed that the time axis has been compressed. That is, when a 10-second audio signal is divided into 150 blocks, one block is approximately 66 meea, which corresponds to the period of two frames of the video signal, that is, the time required for two rotations of the disk 1 in FIG. In this embodiment, 150 blocks are compressed on the time axis to about 33 m5ec and recorded in 7 rotations (frames) of the disk 1. 55 seconds of audio signal
The point that time axis compression can be performed and recorded in m5ec has been mentioned above, so it will be omitted here.

In FIGS. 1 and 3, when the control code detector 8 detects the control code 22 during the first rotation of the disk 1, the first two blocks 24 and 25 of the divided audio signal are detected as part A. A2 is stored in memories 11 and 12. At that time, control code 30 is activated and switch 10 is turned on.
is connected to the memory 11 side, and the control code 51 connects the switch 10 to the memory 12 side. Then control code 3
6, the disk 1 starts rotating for the second time and plays back the track on which the video signal is recorded.

At this time, the cutoff circuit 15 is made conductive to output the video signal to the video signal output terminal 17, and the switch 1
3 is connected to the memory 11 side, the audio signal whose time axis has been expanded using the block frequency of the memory 11 and the audio signal demodulation circuit is read out from the memory 11, and the audio signal is output to the audio signal output terminal 18 via the cutoff circuit 16 which is in a conductive state.
get to. When the control code 23 comes, the first cutoff circuit is cut off, and the servo loop built in the signal reading device 4 is controlled to jump to the first control code 30 of the frame 1. During this jump through period, the audio signal stored in the memory 11 continues to be output to the audio output terminal 18.

Then, disk 1 starts rotating for the third time, and disk 1
The audio signal is reproduced from frame 1 of , but reading of the time-extended audio signal of block A from the memory 11 is intermittent, and no audio signal is written to the memo 1J11, 12. Then, the control signal 36 is played back, and when the disk 1 starts rotating for the fourth time and the video signal of frame 2 is played back, the cutoff circuit 15 becomes conductive so that the video signal is available at the output terminal 17. However, at the same time, the reading of the time-axis expanded audio signal of block A from the memory 11 is completed (the reading of this block
(This is because the rotation period, that is, 2 frames = 66 msec). Therefore, the changeover switch 13 is connected to the memory 12 side, and the time-axis expanded audio signal of the block A2 is read out from the memory 12 and obtained at the output terminal 18.

After that, the control code 23 is reproduced, the cutoff circuit 15 is cut off, and the disk 1 starts rotating for the fifth time to reproduce frame 1. However, when the control code 32 is reproduced, the changeover switch 10 is switched to the memory 11 side. Connect, block A& is memory 1
Written to 1. The control code 36 is then played;
When the reading of the time axis expanded audio signal of block A2 stored in the memory 12 is completed, the control circuit 9 connects the changeover switch 13 to the memory 11 side, and the control circuit 9 connects the changeover switch 13 to the memory 11 side.
From block A30, the time axis expanded audio signal is output, and when control code 33 is detected thereafter, block A4 is stored in memory 12. After sequentially outputting signals up to block At5o in this way, the cutoff circuit 15
．． 16, and either move to the next still image playback or stop the playback.

As described above, in this embodiment, an audio signal of approximately 10 seconds is transmitted to approximately 666 pixels, which corresponds to the scanning time of 2 frames of disk 1.
The audio signal made up of these 150 blocks is recorded by compressing the time axis into one frame of disk 1, and during playback, the audio signal is divided into 150 blocks of m5eo every 102 rotations (2 frames) of the disk. Since one block is played back and alternately written to two memories, and the audio signal of the block is read out from these memories alternately every two revolutions of disk 1 with time axis expansion, the memory to be used is This means that only two memories are required to store one block of time-axis compressed audio signals. Therefore, the prior art disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 54-27719 compressed the audio signal of about 10 seconds in time axis, recorded it in one frame of the disk, played it back, and wrote the whole thing to the memory. In comparison, in the above embodiment, only a memory with a capacity of about 2/150 bits is required, and the capacity of the memory used can be significantly reduced.

In the above embodiment, the audio signal is divided into 150 blocks so as to be stored in the memory once during the reproduction scanning period of two frames of the disc.
In order to store it in memory once when scanning one frame,
If the audio signal is divided into approximately 75 blocks, approximately 1
The memory capacity required to reproduce a 0 second audio signal is 16 bits, which is twice the above. Thus, it is clear that the present invention is not effective only when the block division is 150 as described above. Furthermore, the number of memories is not limited to two as shown in the above embodiment.

By the way, in the above embodiment, while tracing the audio signal part, 2 frames (approximately 15H) are traced.
During the period of 2), the cutoff circuit 15 is cut off, so no video signal is output to the output terminal 17.
As in the prior art disclosed in Publication No.-70721, 1
Since the signal is not an intermittent signal every horizontal period, there is no shortage of image information, and therefore the image quality does not deteriorate.

In this case, since the video signal is an intermittent signal every other field, there is a possibility that screen flickering called 7 flicker may occur. If flicker is a concern, you can counteract it by increasing the afterglow of the down tube that plays back still images. FIG. 4 shows another specific example of the signal recorded on the disk to further increase the resistance to 17 degrees. In this case, taking advantage of the fact that one frame of the video signal consists of two fields, two fields are combined into one frame.
and the half frame period of frame 2. As in the case of Fig. 3, the audio signal changes from A to A.
The video signal is sequentially reproduced up to 150, and the video signal is alternately reproduced by repeatedly scanning fields V and V2. In addition,
In FIG. 4, 21A, 21B.

25A, 23B, 36A, 5tSB are 2 in Fig. 3.
The control codes are divided into 1.23°36 and indicate the same function.

Furthermore, considering the future prospects of the present invention, there are currently few television systems using IIL 7 frame memory due to the high cost of memory, but in the future television systems with built-in image frame memory ( When a so-called digital television (such as a digital television) becomes a film, it becomes easier to retain the video signal of the previous frame, which has the same effect as increasing the afterglow of a cathode ray tube that reproduces still images.

That is, control code 30 to control code 5 in FIG.
Alternatively, the previous video signal may be stored in the image frame memory during the period in which the audio signals from control code 30 to control code 36A and from control code 23A to control code 56B in FIG. 4 are being traced. K like this
, the present invention can be played back even on current TV receivers,
Furthermore, considering future television display systems, it also has the advantage of being able to stably reproduce still images.

FIG. 5 is a block diagram showing a specific example of a recording system for carrying out the above embodiment, in which 37 is a video signal input terminal, 38 is a video signal modulator, 39 is an audio signal input terminal, and 40 is an audio signal input terminal. Signal modulator, 41 is a control code addition circuit, 42 is a control code generation circuit, 43 is a control code generation circuit, 44 is a synthesis circuit, 45 is a laser light source, 46 is an optical modulator, 47 is a collimator lens, 4B is a focusing lens , 4
9 is a recording disk, and 50 is a motor.

In the same figure, a still image video signal obtained from a Flynder spot scanner or the like is connected to a video signal input terminal 37.
, are applied to the combining circuit 44 via a video signal modulator. The audio signal is subjected to signal processing such as time-base compression through an audio signal input terminal 39% audio signal modulator 40, and a control code generated by a control code generation circuit 42 is added by a control code addition circuit 41, as shown in FIG. The sections of frame 1 shown in 30 to 56 are constructed and added to the synthesis circuit 44. Further, in the synthesis circuit 44, control codes 22 and 25 from the control code generation circuit 43 are added, resulting in time-series signals of control codes 22 and 23 composed of frames 1 and 2 in FIG. The output signal of the combining circuit 44 drives an optical modulator 46 to which laser light from a laser light source 45 is supplied, and the laser light modulated there is transmitted to a collimator lens 4.
7 and the focusing lens 48, the light spot is focused onto the recording surface of the recording disk 49, and the photo beam forming the recording surface is focused.
The resist etc. are exposed. As a result, the output signal of the combining circuit 44 is recorded on the recording disk 49.

In the above embodiment, the tracks formed on the disk are spiral-shaped, but it goes without saying that they may be concentric. Furthermore, the recording order of audio signals and video signals is not limited to the above.

〔Effect of the invention〕

As explained above, since the audio signal can be played in blocks without reducing the amount of information in the video signal, there is no deterioration in still image resolution and the required internal memory capacity of the playback device can be reduced. This excellent effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the method for recording and reproducing audio signals with still images according to the present invention, FIG. 2 is a track pattern diagram on the disk in FIG. 1, and FIGS. 3 and 4 respectively show this disk. FIG. 5 is a block diagram showing a recording system for carrying out the above embodiment. Explanation of symbols 1... Disk 8... Control code demodulator 10... Changeover switch 11.12... Memory 13... Changeover switch 15.16... Cutoff circuit. 2 Figure 3r5A □Call code f4 Figure-1 ◆Gingo

Claims (3)

[Claims] (1) A composite signal consisting of a still image video signal of a unit period and an audio signal divided into multiple blocks and time-axis compressed arranged in time series is arranged in a concentric or spiral shape around multiple times on the disk. The still image video signal recorded on the track is repeatedly reproduced by scanning the plurality of tracks for reproduction, and each time the track of the plurality of rotations is reproduced and scanned, the reproduced audio signal is reproduced one block at a time. Audio signal recording and playback with still images, characterized in that the time axis is expanded to a time length equal to the period of playback scanning of a track, and still images can be played back and audio for the still images can be displayed for a predetermined period of time. method. (2) According to claim (1), the still image video signal and the audio signal are respectively recorded on different tracks of one revolution on the disk. method. (3) In claim (1), the still image video signal is composed of two interlaced fields, and the still image video signal of one field and half of the audio signal are arranged in time series. A first composite signal and a second composite signal in which the still image video signal of the other field and the remaining half of the audio signal are arranged in time series are recorded on different tracks on the disk. A method for recording and reproducing an audio signal with still images, characterized in that: