JPH0466068B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an information recording and reproducing method, and is particularly suitable for application to a video disk device that records and reproduces still image video signals and corresponding audio data. .

[Background technology and its problems]

Conventionally, this type of video disc device forms a spiral recording track on a video disc.
A still image video signal for one frame is recorded on a track for one lap, and an audio signal (message, background music, etc.) related to the still image is recorded on a track for multiple laps adjacent to the recording track of this still image video signal. There is a device that records a still image video signal and reproduces the still image video signal so that when the still image is monitored, the corresponding audio information can be heard at the same time.

Here, while a still image can be reproduced for a desired time by repeatedly scanning the recording track of one frame's worth of still image video signals with a video head, it is necessary to obtain practically sufficient audio information. For this reason, it is necessary to be able to record at least second-long audio signals on as few recording tracks as possible. Conventionally, to solve this problem, the time axis of PCM encoded audio data is compressed several tens of times until it reaches the same frequency as the video signal, and
Similar to the case of video signals, the signal is converted into a frequency modulated signal format and recorded on an audio signal track. When the audio signal recorded on the audio signal track is played back by the same video head as the video signal, it is temporarily stored in the memory circuit, and this stored data is read out while expanding the time axis and converted into audio. By repeatedly playing the video signal during the conversion operation, a still image and its corresponding audio information are simultaneously reproduced.

In this way, in conventional video discs,
As shown in FIG. 1, on one side of one still image video signal track 1, there are a plurality of audio signal tracks 2 recording audio signals corresponding to still images recorded on the still image video signal track 1. are adjacent to each other, and on the other side of this still image video signal track 1 are adjacent a plurality of audio signal tracks 3 recording audio signals corresponding to still images of the adjacent video signal track.

Therefore, when the still image video signal track 1 is repeatedly played back by the video head, crosstalk from the adjacent audio signal tracks 2 and 3 occurs in the playback output, which deteriorates the image quality of the reproduced still image. I couldn't avoid it. Incidentally, since the signal formats of the audio signals recorded on audio signal tracks 2 and 3 are almost the same as the signal format of the video signals recorded on video signal track 1, crosstalk is likely to occur. There is.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and
This is intended to reduce crosstalk from other adjacent tracks when a still image video signal track is reproduced.

[Summary of the invention]

In order to achieve this purpose, the present invention includes:
A still image video signal for one frame is repeatedly recorded on a track for at least three consecutive circuits, and the three
By repeatedly scanning the still image video signal track in the center, which has still image video signal tracks on both sides of the still image video signal tracks for each rotation, by the video head, even if there is crosstalk from adjacent tracks, it is virtually eliminated. Avoid deteriorating image quality.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings. In FIG. 2, 11 is a video disk;
As shown in Figure 3, still image video track section 1
2 is track 12 for at least three consecutive laps.
A, 12B and 12C, each track 1
Still image video signals for the same one frame are recorded in 2A to 12C.

These still image video signal tracks 12A to 12C
Inside, there is an audio signal track section 13 consisting of audio signal tracks 13A to 13Y for a plurality of turns, for example, 32 times, and a black burst track 1 for 4 times.
A black burst track section 14 consisting of tracks 4A to 14D is formed, thus forming a still picture video audio information track group 15 for one unit.

The still image video/audio information track group 15 for one unit is recorded in a continuous manner on a spiral track of the video disk 11, for example, with address codes sequentially added from the inside. Thus, when a desired address signal S1 is designated and inputted by the keyboard 16 during playback, the video head 17
The address position of the video disk 11 in the radial direction is controlled by the access control device 18, so that the video head 17 can access the black burst tracks 14A to 14D and the audio signal track 13A of the still image video audio information track group 15 at the corresponding address. -13Y are sequentially scanned, and then still image video tracks 12A-12C are scanned. When the video head 17 comes to the position to scan the central track 12B among the still image video tracks 12A to 12C for three rotations, the video head 17 scans the central track 12B by the still command signal S2 given to the access control device 18. 12B
The position is controlled by the access control device 18 so as to repeatedly scan the area.

In this embodiment, the video disk 11 is rotated by a drive motor 19 at a speed of 30 rps, and the video head 17 is an optical head.

The still picture video audio reproduction signal S3 thus reproduced by the head 17 is sent out via the reproduction amplification circuit 21 and the frequency demodulation circuit 22. Here, the still picture video audio reproduction signal S3 has a television video signal format as shown in FIG. 4 for a reproduction signal reproduced from one unit of still picture video audio information track group 15.

In FIG. 4, first and second field signal portions F1 and F2 are reproduced from each one-round track. As the video head 17 scans the black burst tracks 14A to 14D (FIG. 3), a black burst signal section T1 consisting of horizontal and vertical synchronizing signals and burst signals continues for four frames, and then the audio signal tracks 13A to 13Y (FIG. 3) are scanned. A 32-frame audio data section T2 follows by scanning the still image video tracks 12A-12C (FIG. 3), followed by a 3-frame still image video signal section T3 by scanning the still image video tracks 12A-12C (FIG. 3).
Thus, when the video signal section T3 ends, the reproduction of one unit of the still image video and audio signal section TA for the still image ends.

In each frame section of the still image video signal section T3, two fields of video signals having a standard television signal format are recorded, and the contents of the still images are the same.

On the other hand, in each frame section of the audio data section T2, as shown in FIG. In addition to being able to insert the HD, the second
A trailer mark signal TL indicating the end of audio data can be inserted in the 262nd horizontal synchronization interval immediately before the start of the vertical synchronization signal in the field interval F2, and
A time-base compressed audio data signal AT as shown in FIG. 6 can be inserted into the remaining horizontal synchronization sections of F1 and F2. But actually the fourth
As shown in the figure, the header mark signal HD is inserted only in the first frame of the audio data section T2, and the trailer mark signal TL is inserted in the last frame.
It is inserted only in the 32nd frame, thus indicating that the section in which the audio data is inserted is the 1st to 32nd frames.

Furthermore, as shown in FIG. 6, the audio data signal AT in the audio data section T2 is formed by inserting effective audio data DT following the horizontal synchronizing signal H and color burst signal CB, and has a 2-bit width for one period at the leading position. A reference signal ID consisting of a sine wave that changes around the 1/2 amplitude position is inserted, and when the effective audio data DT is played back, the reference signal ID is generated by slicing this audio data DT at the 1/2 amplitude level. This makes it possible to reproduce a reference logic signal with a duty ratio of 50%, a reference bit width, and alternately switching between logic levels "1" and "0", and this reference logic signal has a predetermined waveform. The digital value of the effective audio data DT can be reproduced without error while adjusting the amplitude of the effective audio data DT so that the following is achieved.

In this embodiment, the audio data DT has an effective capacity of 15 bytes for each 1H section. Therefore, as shown in Fig. 7, the data format of one frame of audio data DT has 15 bytes of header signal HD data in the 21st H for the first field F1, followed by 240H data in the 22nd to 261st H. Each interval has effective audio data DT of 15 bytes (therefore, 15×240=3600 bytes). Also, regarding the second field F2, the 22nd to 261st H
15 bytes in each 240H section (therefore 15 x 240
= 3600 bytes), followed by a 15-byte trailer signal TL at the 262nd H.
It has data of Thus, one frame of audio data has a data capacity of 3600 x 2 = 7.2 kilobytes. Then, audio data section T2 (fourth
(Fig.) is composed of 32 frames, so the total capacity of the audio data signal AT during this section T2 is 7.2 x 32 = 230.4 kilobytes, as shown in Fig. 8.

Therefore, if the data format in the audio data section T2 is configured as described above in FIGS. 6 to 8, approximately 1.3
It is possible to reproduce an audio signal of about [sec].

In this embodiment, control program data CP of, for example, 3456 bytes is inserted into the first frame of the audio data section T2, as shown in FIG. It is designed to control the

In addition to the above configuration, as shown in FIG. 8, a used track number display section UT of a predetermined capacity is provided in the leading area of each frame of the effective audio data DT, thereby recording the audio signal related to the still image. Track number data representing the number of tracks (of the video disc 11) can be inserted. In this example, the used track number display section
UT is chosen to be 32 bytes.

The track number data is repeatedly recorded in this display section UT, so that when the reproducing circuit repeatedly reads the same data in this display section UT, it can correct errors in the track number reproduced data based on the majority voting principle. is being done.

In this way the still image video audio playback signal S3
is connected to the video playback circuit 26 through the mute circuit 25.
and the audio signal digital conversion circuit 27. The video reproduction circuit 26 and the conversion circuit 27 operate in synchronization upon receiving the signal of the black burst section T1 of the audio/still image video/audio reproduction signal S3, and the monitor 28 is brought into a state where a still image is displayed, and the audio is output from the audio data section T2. A state is reached in which a digital signal corresponding to the data is obtained.

In this way, when the header mark signal HD of the audio data signal AT is sent out from the audio signal digital conversion circuit 27, the header mark detection circuit 31 detects it and uses the detection signal S11 to thereafter turn off the mute circuit 25 and perform frequency demodulation. The passage of signal S3 from circuit 22 to video playback circuit 26 is interrupted. This state continues until the trailer mark detection circuit 32 detects the trailer mark signal TL of the audio data signal AT when it is sent out from the audio signal digital conversion circuit 27 and resets the header mark detection circuit 31 using the detection signal S12. maintained.

Further, the header detection signal S11 is given to the temporary storage memory circuit 33 as a write enable signal,
Thus, in the conversion circuit 27, the header mark signal
Every time digital data corresponding to the first to 32nd frame signals (FIG. 4) of section T2 subsequent to HD is obtained, it is stored in the memory circuit 33. This data storage operation is performed by a write clock pulse S14 sent from the clock control circuit 34 which operates in synchronization with the horizontal synchronization signal S13 obtained in the conversion circuit 27.
executed by. In this way, the memory circuit 33 stores all the time-base compressed audio data in the audio digital signal format (32 frames).

When the audio data AT has been stored in the memory circuit 33 and the trailer mark detection signal TL is sent out from the detection circuit 32, it is delayed by the delay circuit 35 and obtained as the still image generation start command signal S15. This delay circuit 35 has a delay time of only one frame section (therefore, two vertical synchronization sections) of the reproduced still image video and audio signal S3 (FIG. 4), and thereby the still image signal section T3 (FIG. 4). A command signal S15 is sent out at the timing when the still image signal of the second frame is sent out from the conversion circuit 27, and this is given to the access control device 18 as a still command signal. At this time, the access control device 18
7 are still image video signal tracks 12A to 12C
The position of the head 17 is controlled to repeatedly scan the center track 12B currently being scanned (FIG. 3).

At the same time, a still image generation start command signal S15 is given to the error correction circuit 36. At this time, the error correction circuit 36 sequentially reads out the audio data stored in the memory circuit 33 and corrects the errors, and then converts the audio data into an analog signal format audio signal S16 by the digital-to-analog conversion circuit 37.
is applied to the speaker 40 through the amplifier circuit 38.
Here, the read operation in the clock control circuit 41 of the memory circuit 33 and the conversion operation in the digital-to-analog conversion circuit 37 are performed by the clock signal S17 of the clock generator 42.
The period of S17 is selected to be a sufficiently large value compared to the reading period when each audio data is read into the memory circuit 33, so that the audio data AT is expanded on the time axis, read out from the memory circuit 33, and converted into an analog signal. In this way, an audio signal of a regular frequency is provided to the speaker 40.

The read operation state of the memory circuit 33 is limited by a read time limit circuit 45 so that it does not exceed a predetermined time. That is, the read time limit circuit 45 receives the still image generation start command signal S15 from the track number data gate control circuit 46. This gate control circuit 46 controls 32-byte track number data inserted into the first section UT of the first frame of the audio data DT (FIG. 8) stored in the memory circuit 33.
S18 is passed through the gate circuit 47 to the error correction circuit 48.
be incorporated into. At this time, the error correction circuit 48 receives track number data that repeatedly arrives based on the majority rule.
After correcting the error in S18, it is applied to the decoder 49, and the recorded data in the read range corresponding to the number of tracks is specified to the read control circuit 50 of the memory circuit 33, so that the memory circuit 33 reads out the data in this specified range. When this happens, further reading operations are stopped.

In the above configuration, when the still image of the n-th unit is specified by the keyboard 16, the access control device 18 moves the head 17 to the video disk 11.
The still image video/audio signal track group 15 (FIG. 3) of the n-th unit is positioned, and scanning of the black burst tracks 14A to 14D is started.
At this time, the frequency demodulation circuit 22 sends out the black burst section T1 of the still picture video audio reproduction signal S3, which is given to the video reproduction circuit 26 through the mute circuit 25 which is in the ON operation, and is also applied to the audio signal digital conversion circuit 27. Given.

Before long, the head 17 receives the audio signal track 13A~
13Y starts to be scanned, the audio data section T2 of the still image video audio reproduction signal S3 comes to be sent out from the frequency demodulation circuit 22. Since the header mark HD is inserted in the first frame, the header mark detection circuit 31 detects this, and the detection signal S11 turns off the mute circuit 25 and sets the memory circuit 33 to the write enable state. The first to first signals are converted into digital signals by the audio signal digital conversion circuit 27.
Thirty-two frames of audio data DT are stored in the memory circuit 33.

When the storage of this audio data DT is completed, it is detected by the trailer mark detection circuit 32 detecting the trailer mark TL inserted in the last frame (that is, the 32nd frame), and the detection signal S12 is Therefore, the detection operation of the header mark detection circuit 31 is reset, so that from now on the head 17 detects the still image video tracks 12A to 12A.
When the scanning of 12C is started, the video signal of the still image video signal section T3 generated in the still image video audio reproduction signal S3 is given to the video reproduction circuit 26 and the monitor 2 is outputted.
8 will be displayed.

The detection signal S12 of the trailer mark detection circuit 32 is delayed by two vertical synchronizing signal sections (therefore, one frame section) by the delay circuit 35 and is given to the access control device 18 as a still command signal S2.
The timing of this still command signal S2 coincides with the timing at which the head 17 starts scanning the still image video track 12B (FIG. 3) in the central area, and therefore the access control device 18 repeats the scanning of the still image video track 12B (FIG. 3) in the central area. The still image video track 12B is now in a state of being scanned. Therefore, the still picture video audio reproduction signal S3 of the frequency demodulation circuit 22 becomes in a state where the second frame (FIG. 4) of the still picture video signal section T3 is repeatedly reproduced, and thus the n-th frame is displayed on the monitor 28.
A still image of the unit will be repeatedly reproduced.

While this still image is being reproduced on the monitor 28, the output signal S15 of the delay circuit 35 starts the operation of the error correction circuit 36, which causes the memory circuit 33 to output the clock signal S15 of the clock generator 42.
Reading is started at the cycle of S17, and thus the audio data stored in the memory circuit 33 is read out while being expanded on the time axis, converted by the digital-to-analog conversion circuit 37, and sent out as audio information from the speaker 40.

Therefore, it is possible to view still images on the monitor 28 while listening to audio information from the speaker 40.

At the same time, the output signal S15 of the delay circuit 35 is applied to the track number data gate control circuit 46 of the read time limit circuit 45 to open the gate 47.
At this timing, the audio data DT of the first frame of the audio data section T2 of the memory circuit 33 starts to be read, so the used audio data track number data (FIG. 8) inserted in the leading area UT of this first frame is It will be taken in from the gate circuit 47. Therefore, the read control circuit 50
is the number of audio data tracks used (in this example
Audio data corresponding to 32 tracks (Figure 3)
The DT is read from the memory circuit 33, and after the reading is completed, the reading operation of the memory circuit 33 is restricted.

In this way, the audio information recorded on the audio signal track 13 of the video disc 11 after time-base compression is reproduced without excess or deficiency.

In the above description, all 32 audio signal tracks 13A to 13Y are used to record audio information on the video disk 11, but the number of tracks used can be varied as necessary. In this case, track number data representing the number of tracks actually used may be recorded in the leading area UT of the audio signal track, and based on this data, the read time limit circuit 45 controls the memory circuit 3.
This limits the readout time of 3.

In addition, in the above example, the video disk 11 has 3
still image video tracks 12A, 12B and 1
2C records the same still image video signal, and the central track 12B is repeatedly scanned by the video head 17; however, the present invention is not limited to this.
Still image video information is obtained by recording the same still image video signal on two or more still image video tracks and repeatedly scanning the tracks on which the same still image video signals are recorded on both sides of the track. It's okay.

Furthermore, in the above description, an example was described in which audio data was recorded on 32 tracks.
The same effect as described above can be obtained even if the data is recorded on one or more tracks.

〔Effect of the invention〕

As described above, according to the present invention, when recording a still image video signal on a video disk, the same still image video signal is recorded on at least three still image video tracks, and the still image video track in the center is recorded on at least three still image video tracks. By repeatedly scanning the still image with the video head, it is possible to prevent the image quality of the still image from deteriorating due to crosstalk from other adjacent tracks.

Incidentally, even if crosstalk occurs from actually adjacent tracks during repetitive scanning by the head, since the same still image video signal as the track being repeatedly scanned is recorded on the adjacent tracks, virtually no reproduced still images will be generated. This can be done without degrading the image quality.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a recording track of a conventional video disc, Fig. 2 is a block diagram showing a reproducing circuit to which the information recording/reproducing method according to the present invention is applied, and Fig. 3 shows a recording track of the video disc. Schematic diagrams, FIGS. 4 to 6 are signal waveform diagrams showing the still image video audio reproduction signal of FIG. 2, and FIGS. 7 and 8.
The figure is a schematic diagram showing the data structure. 11...Video disk, 12...Still image video track section, 13...Audio signal track section, 14...Black burst track section, 1
7... Video head, 18... Access control device, 22... Frequency demodulation circuit, 26... Video signal reproducing circuit, 27... Audio signal digital conversion circuit, 31... Header mark detection circuit, 32... Trailer mark detection Circuit, 35...Delay circuit, 45
...Reading time limit circuit.

Claims (1)

[Claims] 1 Recording a still image video signal in a first track section of the spiral tracks of a video disk, and recording an audio signal corresponding to the still image video signal in a second track section, The audio signal obtained by scanning the section with the video head is temporarily stored in a memory circuit, and the audio signal of the memory circuit is read out to reproduce the audio information while the video head scans the first track section. A still image is reproduced by repeated scanning, the first track section is made up of tracks for at least three laps, and the same still image signal is recorded on the track for each lap. An information recording and reproducing method characterized in that the video head repeatedly scans a central track having tracks on both sides of which the same still image signal is recorded.