JPH0638155A - Disk reproduction method - Google Patents

Abstract

(57) [Summary] [Object] To prevent the screen from being disturbed during variable speed reproduction in a CAV video disc in which a high definition video signal is recorded as a MUSE system signal. [Structure] The optical head 3 reproduces a video signal recorded on a video disk 1 and outputs the reproduced video signal to a demodulation circuit 4.
The demodulation circuit 4 demodulates the input RF signal and outputs it to the reproduction video processing circuit 5. The reproduction video processing circuit 5 processes the demodulated signal and outputs it from the output terminal 6. During variable speed reproduction, the CPU 9 controls the optical head 3 to jump at a predetermined timing. This jump is always performed on the corresponding field among the first to fourth fields.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing method suitable for use in variable-speed reproduction of a video disc recorded with a high-definition type video signal as a MUSE type signal.

[0002]

2. Description of the Related Art Video discs include CLV discs and CAV discs. Since a CLV disc records a video signal so that the linear velocity is constant, more video signals can be recorded toward the outer periphery,
It becomes possible to record a video signal for a long time on one disc. On the other hand, a video signal is recorded on the CAV disc so that the rotation angular velocity is constant. As a result, for example, one frame of video signal is recorded for one rotation of the disk, and variable speed reproduction is possible in addition to still image reproduction.

[0003]

By the way, in the conventional video disc, when variable speed reproduction is performed, the optical head is made to perform track jump in units of one field. As a result, for example, when variable speed playback is performed on a video disc on which a high-definition video signal is recorded, the image before the variable speed playback is overlapped with the image during variable speed playback, the screen is distorted, color jumps occur, and the screen becomes difficult to see. was there.

The present invention has been made in view of such a situation, and is intended to prevent the screen from being disturbed during variable speed reproduction.

[0005]

According to the disk reproducing method of the present invention, the pixels at a predetermined position constituting one screen are divided into four groups, first to fourth, and the data of the pixels of the first group is divided. Are arranged in the first field, the data of the pixels of the second group are arranged in the second field,
The data of the pixels of the third group is arranged in the third field, the data of the pixels of the fourth group is arranged in the fourth field, and the video signal of one frame is recorded in one rotation. In a disc reproducing method for reproducing a CAV disc at a variable speed, the operation of always jumping to a corresponding field among the first to fourth fields is repeated during the variable speed reproduction.

[0006]

In the disc reproducing method having the above structure, the jump is always performed in the corresponding field during the variable speed reproduction. Therefore, it is possible to prevent the screen from being disturbed during variable speed reproduction.

[0007]

1 is a block diagram showing the construction of an embodiment of a video disc player to which the disc reproducing method of the present invention is applied. A high-definition video signal is recorded on the video disc 1 as a MUSE signal. The video disc 1 is rotated by a spindle motor 2, and the recorded video signal is reproduced by the optical head 3. The output of the optical head 3 is input to the demodulation circuit 4 and demodulated. The demodulation output of the demodulation circuit 4 is supplied to the reproduction video processing circuit 5 and processed (encoded). Then, this video signal is output from the output terminal 6.

The signal output from the demodulation circuit 4 is also supplied to the synchronization signal separation circuit 7. The sync signal separation circuit 7
The synchronizing signal is separated from the input signal and supplied to the spindle servo circuit 8 and the CPU 9. The spindle servo circuit 8 supplies a drive signal to the spindle motor 2 via the driver 10 so as to drive the spindle motor 2 in synchronization with the synchronization signal. Further, the CPU 9 outputs a track jump command to the optical head 3 in synchronism with the sync signal to jump the reproduction position to a predetermined track.

FIG. 2 shows a recording format in the video disc 1. As shown in the figure, synchronization signals V _O1 , V _E1 , V _O2 , and V _E2 are recorded at the beginning of the field. Then, audio data A _{1 to} A ₄ are respectively arranged in the area following the audio data. Further, the video data V _O1 , V _E1 , V _O2 , and V _E2 are recorded next, and further various codes are recorded after that. Video data V _O1 , V _E1 , V _O2 , V
_E2 is obtained by dividing the pixel data forming one image into four groups and arranging the pixel data of each group. Therefore, one image data is completed for the first time by collecting all the video data of 4 fields (2 frames). A video signal of one frame is recorded on the video disc 1 in one rotation.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to FIG.
This will be described with reference to the flowchart shown in FIG. CP first
When a command for speed change reproduction is input from an operation unit (not shown), U9 determines the kind of speed change in step S1. Then, in step S2, the number and direction of track jumps required for variable speed reproduction are determined. The number and direction of this track jump is determined as follows. In addition, + means a jump in the outer peripheral direction, and-means a jump in the inner peripheral direction. (1) + 2n times speed (n is an integer of 0, 1, 2, 3, ...) The jump of 2 (2n-1) tracks is repeated every two frames. (2) In the case of + 2n + 1 double speed, the jump of 2n tracks is repeated every frame. (3) In the case of 2n speed, -2 (2n + 1) =-(2 (2n-1)) every two frames
+4) Repeat the track jump. (4)-(2n + 1) double speed: The jump of -2 (n + 1) tracks is repeated for each frame. (5) + 1 / (2n) double speed: -2 (2n-1) track jumps are repeated every 4n frames. (6) In the case of + 1 / (2n + 1) times speed, the jump of -4n tracks is repeated every 2 (2n + 1) frames. (7) In the case of -1 / (2n) double speed, the jump of -2 (2n + 1) tracks is repeated every 4n frames. (8) -1 / (2n + 1) double speed, the jump of -4 (n + 1) tracks is repeated every 2 (2n + 1) frames.

The above-mentioned eight kinds of double speed reproduction methods are the simplest examples, and various modifications can be considered. For example, 1 /
In the case of quadruple speed, in the above method (5), -6 tracks are jumped every 8 frames. However, after reproducing 4 frames, -2 tracks are jumped,
It is also possible to realize the quarter speed by repeating the operation of jumping -4 tracks after reproducing 4 frames again.

After step S2, the process proceeds to step S3,
The presence or absence of a sync signal is determined. That is, the signal reproduced from the video disk 1 by the optical head 3 is demodulated by the demodulation circuit 4 and supplied to the sync signal separation circuit 7. The sync signal separated by the sync signal separation circuit 7 is sent to the CPU 9
Is being supplied to. The CPU 9 determines the presence or absence of this synchronization signal in step S3. When the sync signal is detected, the process proceeds to step S4 to generate a track jump timing signal.

Thereafter, the process proceeds to step S5, and a track jump command is generated with reference to the timing signal generated in step S4. This track jump command is supplied from the CPU 9 to the optical head 3. The optical head 3 executes a track jump in response to this track jump command (step S6).

Next, in step S7, it is determined whether or not the end of the variable speed reproduction is instructed. If the end is not instructed, the process returns to step S3, and the subsequent processes are repeatedly executed. If it is determined in step S7 that the end of variable speed reproduction has been instructed, step S8
Then, the process shifts to normal reproduction, and the subsequent processes are executed.

In this way, when the track jump is repeatedly executed, the signal output from the demodulation circuit 4 is processed by the reproduction video processing circuit 5 and output from the output terminal 6 to a CRT or the like (not shown) for display. . As a result, the variable speed reproduction screen is obtained.

Next, the video signal (frame) reproduced during variable speed reproduction will be described with reference to FIGS.

FIG. 4 shows an example of +2 times speed. This variable speed reproduction corresponds to the case where n = 1 is substituted at the + 2n times speed in the above (1). Therefore, only two tracks are jumped every two frames. That is, the odd field O as the first field
After a two-frame video signal consisting of an even field E1 as a first field, an even field E2 as a third field, and an even field E2 as a fourth field is reproduced, for example, field E2
In, the jump is performed in the + direction (outer peripheral direction) for only two tracks.

Since the video disc 1 is a CAV disc in which one frame of video signal is recorded in one rotation, the outer tracks of the two tracks are also the even field E2 as the fourth field. Therefore, only the two frames are continuously reproduced from the field E2 after the jump. That is, at this time, fields E2 and O
The video signals are sequentially reproduced in the order of 1, E1, O2 and E2. Then, in the field E2, the outer track is jumped again by two tracks.

Since the types of fields correspond to each jump position, the data before the jump and the data after the jump have time-shifted data, but the type of pixel data (screen The position of the pixel above) does not change before and after the track.
Therefore, the reproduction video processing circuit 5 uses the pixel data obtained after the jump as the pixel data obtained before the jump.
Even if the processing is performed by the (encoder), the screen is not greatly disturbed.

FIG. 5 shows an example of +3 times speed. This example corresponds to the case where n = 1 at + 2n + 1 times speed in the above (2). That is, at this time, the jump of two tracks is repeated for each frame. In FIG. 5, the even field E as the fourth field
2. After the odd field O1 as the first field and the even field E1 as the second field are sequentially reproduced, a jump is made to the outer circumference of two tracks in the field E1. As described above, since the tracks on the outer circumference of the two tracks are the fields corresponding to the tracks before the jump, this track is also the even field E1 as the second field. Then, following the second field E1, the odd field O2 as the third field and the even field E2 as the fourth field are sequentially reproduced. In field E2,
The jump is executed again by 2 tracks to the outer circumference. The same jump is repeated thereafter.

Even when such a jump is repeated, four kinds of fields including the first field to the fourth field are reproduced in order.

FIG. 6 shows an example of +4 times speed. The quadruple speed corresponds to the case where n of the + 2n times speed in the above (1) is set to 2. Therefore, at this time, a jump of 6 tracks is repeated every 2 frames. In FIG. 6, after the fields O1, E1, O2, E2 are sequentially reproduced, a jump is made to the outer circumference of 6 tracks in the field E2, and from there, fields E2, O1, E1,
Two frames, O2 and E2, are reproduced. Then, in the field E2, a jump is again made to the outer circumference of 6 tracks.

FIG. 7 shows an example of +5 times speed. This corresponds to the case of n = 2 where n is + 2n + 1 times the speed of (2) described above. Therefore, at this time, the jump of four tracks is repeated every frame.

FIG. 8 shows an example of +6 times speed. The 6 × speed is 3 as n of + 2n times speed in (1) above.
Corresponds to when is substituted. Therefore, in this case, a jump of 10 tracks is performed every two frames.

FIG. 9 shows an example of +7 times speed. The 7 × speed is n = 2 ++ 1 in (2) above.
It corresponds to the case of 3. Therefore, in this case, 6 tracks are jumped for each frame.

FIG. 10 shows an example of +8 times speed. 8
Double speed corresponds to the case where n = 4 at + 2n double speed. Therefore, 14 tracks are jumped every 2 frames.

FIG. 11 shows an example of -1 × speed. −
The 1 × speed corresponds to the case where n = 0 is substituted as −n in the − (2n + 1) times speed of (4) described above. Therefore, in this case, a −2 track jump is performed for each frame. That is, a two-track jump is performed on the inner circumference side for each frame.

FIG. 12 shows an example at -2 speed. −
The double speed corresponds to the case where 1 is substituted as n of the −2n double speed in the above (3). So in this case,
A -6 track jump is performed every two frames.

FIG. 13 shows an example of -3 × speed. −
The triple speed corresponds to the case where 1 is substituted as n in the-(2n + 1) double speed. Therefore, in this case, a -4 track jump is performed for each frame.

FIG. 14 shows an example of -4 × speed. −
The 4 × speed corresponds to the case where 2 is substituted as n at −2n times speed. Therefore, in this case, a jump of -10 tracks is performed every two frames.

FIG. 15 shows an example of -5 times speed. −
The 5 × speed corresponds to the case where 2 is substituted as n in − (2n + 1) × speed. Therefore, in this case, a jump of -6 tracks is performed for each frame.

FIG. 16 shows an example of -6 × speed. −
The 6 × speed corresponds to the case where n = 3 is substituted at the −2n speed. Therefore, in this case, -14 every two frames
A track jump is performed.

FIG. 17 shows an example of -7 times speed. −
The 7x speed corresponds to the case where n = 3 is substituted in the-(2n + 1) x speed. Therefore, in this case, a jump of -8 tracks is performed for each frame.

FIG. 18 shows an example of +1/2 speed. The 1/2 speed corresponds to the case where 1 is substituted as n for the 1 / (2n) speed. Therefore, in this case,
A jump of -2 tracks is performed every four frames.

FIG. 19 shows an example of +1/3 speed. 1/3 double speed is 1 as n of 1 / (2n + 1) double speed
Corresponds to when is substituted. Therefore, in this case, a jump of -4 tracks is performed every 6 frames.

FIG. 20 shows an example of -1/2 speed. -1/2 speed is 1 as n of -1 / (2n) speed.
Corresponds to when is substituted. Therefore, in this case, a jump of -6 tracks is performed every 4 frames.

FIG. 21 shows an example of -1/3 speed. -1/3 times speed corresponds to the case where 1 is substituted as n of -1 / (2n + 1) times speed. Therefore, in this case, a jump of -8 tracks is performed every 6 frames.

[0038]

As described above, according to the disc reproducing method of the present invention, during variable speed reproduction, the operation of always jumping to the corresponding field among the first to fourth fields is repeated. , It is possible to prevent the screen from being disturbed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a video disc player to which a disc reproducing method of the present invention is applied.

FIG. 2 is a diagram illustrating a format in the video disc 1 of FIG.

FIG. 3 is a flowchart illustrating the operation of the embodiment of FIG.

FIG. 4 is a timing chart for explaining the operation at + 2 × speed in the embodiment of FIG.

5 is a timing chart for explaining the operation at +3 times speed in the embodiment of FIG.

FIG. 6 is a timing chart for explaining the operation at + 4 × speed in the embodiment of FIG.

FIG. 7 is a timing chart for explaining the operation at + 5 × speed in the embodiment of FIG.

FIG. 8 is a timing chart for explaining the operation at + 6 × speed in the embodiment of FIG.

FIG. 9 is a timing chart for explaining the operation at + 7 × speed in the embodiment of FIG.

FIG. 10 is a timing chart for explaining the operation at + 8 × speed in the embodiment of FIG.

FIG. 11 is a timing chart for explaining the operation at −1 × speed in the embodiment of FIG.

FIG. 12 is a timing chart for explaining the operation at −2 × speed in the embodiment of FIG.

FIG. 13 is a timing chart for explaining the operation at −3 × speed in the embodiment of FIG.

FIG. 14 is a timing chart for explaining the operation at −4 × speed in the embodiment of FIG.

FIG. 15 is a timing chart illustrating an operation at −5 × speed in the embodiment of FIG.

16 is a timing chart for explaining the operation at −6 × speed in the embodiment of FIG.

FIG. 17 is a timing chart for explaining the operation at −7 × speed in the embodiment of FIG.

FIG. 18 is a timing chart illustrating an operation at 1/2 speed in the embodiment of FIG.

FIG. 19 is a timing chart for explaining the operation at 1/3 speed in the embodiment of FIG.

FIG. 20 is a timing chart for explaining the operation at −½ speed in the embodiment of FIG.

FIG. 21 is a timing chart for explaining the operation at −1/3 speed in the embodiment of FIG.

[Explanation of symbols]

 1 Video Disc 3 Optical Head 4 Demodulation Circuit 5 Playback Video Processing Circuit 7 Synchronous Signal Separation Circuit 8 Spindle Servo Circuit 9 CPU

Claims (4)

[Claims] 1. A pixel at a predetermined position forming one screen is divided into four groups of first to fourth, and the first pixel is divided into four groups.
Data of the pixels of the second group are arranged in the first field, and data of the pixels of the second group are arranged in the second field.
Data of the pixels of the third group are arranged in a third field, and the data of the pixels of the fourth group are arranged in a fourth field. In a disc reproducing method for variable-speed reproduction of a CAV disc in which a video signal is recorded in one rotation, in the variable-speed reproduction, an operation of always jumping to a corresponding field among the first to fourth fields is repeated. How to play a disc. 2. The disc reproducing method according to claim 1, wherein the jump is performed in units of even tracks. 3. The disc reproducing method according to claim 1, wherein the jump is performed in the outer peripheral direction of the disc. 4. The disc reproducing method according to claim 1, wherein the jump is performed in an inner peripheral direction of the disc.