JPS63146582A - Optical video disk reproducing device - Google Patents

Abstract

PURPOSE:To attain the same special reproduction as a disk by a CAV system in reproducing a video disk by the CLV system by providing a video memory storing once and outputting a video signal frame extracted by the optical pickup from the disk of the constant linear velocity system. CONSTITUTION:Changeover switches sw1, sw2 are thrown to the position (b) at a time (t) when the frame (n) of a video signal reaches. A control circuit 22 sends the frame (n) to a DA conversion circuit 23 through the switch sw2 and stores the data into a memory circuit 24. At a frame end time (t+1), the switch sw1 is restored to the position (a), and the switch sw2 remains kept to the position (b) as it is. The control circuit 22 reads a signal from the memory circuit 24 repetitively continuously and sends it to the DA conversion circuit 23. In this case, the optical pickup 14 is stopped. That is, a tracking motor 15 is stopped. Thus, the stop motion reproduction is realized by the CLV system.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an optical video disc playback device.

[Conventional technology]

Traditionally, optical video discs have a G
Two types have become popular and are in practical use: the AY direction angular velocity - construction method) and the CLv method (constant linear velocity method). The CAV method is a method in which a disk is rotated at a constant rotation speed and one frame is recorded on one track. Further, the CLV method is a method in which the rotational speed is lowered toward the outer tracks, and the linear velocity of the tracks is kept constant throughout during image reproduction.

This will be explained with reference to the drawings. Figure 1 1cAV
This is a simple diagram of the tracks on a disc using this method. 1 is the outer circumference of the disk, 2 is the inner circumference of the disk, 3
One of the trucks? It shows. 4 at frame boundaries on that track, one frame per track - 5
is recorded. During normal video playback, the pickup scans the tracks at a rate of 30 tracks per second, but by changing this scan speed, variable speed playback including stop motion can be performed. FIG. 2 is a simple diagram showing the track state of a BCLV type disk. 1
2 shows the outer circumference of the disk, 2 shows the inner circumference of the disk, and 3 shows the track. 4 shows two of the frame boundaries on track 3. This is one frame sandwiched between 5 frames. In this CLV method, the information density is the same at all positions on the disc, so a large amount of information can be recorded per disc.

[Problem that the invention seeks to solve]

The GAY method described above records one entire frame on one track, so special playback such as single frame playback and variable speed playback can be performed by fully controlling the playback track position, but the recording density of the entire disc There is a problem that the non-recording time cannot be increased due to the low value of recording. On the other hand, since multiple frames are all recorded on one track in the CLV format, the recording density of the entire disc can be high and long playback is possible, but since multiple frames are all recorded on one track, The problem is that it cannot be played.

[Means for Solving the Problem No. 5] The original type video disc playback device of the present invention a has a video memory which stores and outputs video signal frames extracted by the original pickup from a constant speed recording type disc. .

〔Example〕

Next, embodiments of the present invention will be described with reference to all the drawings.

3 is a diagram illustrating an optical video disk reproducing apparatus according to an embodiment of the present invention; FIG. 11 is a disk, 12 is a drive motor that rotates the disk 11, 13 is a control circuit for the drive motor 12, 14 is a charging pickup, 15 is a tracking motor that changes the position of the original pickup 14, 1
6 is a control circuit for the motor 15, 17 is an original detection circuit, 18 is a video and audio detection circuit, 19 is a video and audio amplification circuit, and 20 is a video memory. During normal playback, the signal extracted by the original pickup 14 passes through the optical detector Vi, the circuit 17, the video/audio detection circuit 18, the video memory 20, and the video/audio amplification circuit 19, and is taken out as a composite video signal. Here, by providing the video memory 20 between the video and audio detection circuit 18 and the video and audio amplification circuit 19, the present invention allows arbitrary frames to be stored and taken out by fully adjusting the timing. This is a feature of To be more specific, the video memory 20 includes an All conversion circuit 21, a memory write/read control circuit 22, and an L)A conversion circuit 2.
3, a memory circuit 24, and changeover switches 8W1 and 8W2. At is applied to the video signal extracted by the detection circuit 18.
) The entire conversion circuit 21 is stored in the memory circuit 24. The signal stored in the memory circuit 24 is taken out by the control circuit 22 and sent to the video/audio amplifier circuit 19 via the IJA transformation circuit 23.

A more detailed explanation of the operation will be given with reference to FIG. Figure 4 shows the relationship between the frame signal included in the signal of a V-system disc and the position on the track.At time t when frame n of the video signal arrives, the changeover switch swl, 5w2ib is turned on. 1) Switch the frame n to the control IP! circuit 22 through the switch SW2 to the A conversion circuit 23, and send it to the memory circuit 24.
Record data to. At frame end time t+1, return to switch SW1'ka and switch 5W2H No. 11
Set it to b. This time, the memory circuit 24 is connected to the control 1g approximately 22.
is repeatedly and continuously read out and sent to the LIA change circuit 23. At this time, the pickup 14 is stopped.

That is, the tracking motor 15 is stopped. In this way, it is possible to realize stave motion playback on a CLV type disc. When reproducing the next frame n+1, all original pickups 14 are moved back a little, all tracking motors 15 are activated, and the beginning of frame n+1, t+1
At the point in time, switch Swl is fully turned down and the same operation is performed.

By repeating this series of operations at specific intervals, special playback such as slow motion can be achieved. That is, it is possible to select only one specific frame from among a plurality of frames reproduced from a CLV disc and reproduce it continuously or sequentially. Also, when returning to normal continuous playback, press switch s.
Set both w1 and sw2 to the a side and pick up 1
By restoring all of the tracking in 4, you can return to the original mode.

[Effects of the invention] As explained above, non-invention has the following effects.

(1) In addition to playing video discs based on the CLV system, it is possible to perform the same special playback as on discs based on the eAV system.

(2) The CLV method can be used as a recording method for companion disks for the purpose of special playback, and the amount of information stored per disk can be increased.

(3) Increasing the number of screens that can be stored, especially for still image discs.
can be increased to

(4) Fully compatible with conventional devices.

(5) Since the structure is such that all the circuits that are slightly Wr-friendly are added to the conventional playback device, no changes are required to the mechanical parts of the conventional device.

[Brief explanation of the drawing]

Figure 1 shows the entire track structure of a CAv type disc [1
, 82 is a diagram showing the track structure of a CLV system disc, FIG. 3 is a block diagram showing an embodiment of an uninvented original type video disc playback device, and FIG. 4 is an optical video disc valve of the same embodiment. This is a diagram explaining the operation of the production equipment. 11...disc, 14...original pickup, 17
... Original detection circuit, 18 ... Video and audio detection circuit, 19
...-video and audio amplification circuit, 20... video memory.

Claims (1)

[Claims] An optical video disc playback device comprising a video memory that temporarily stores and outputs video signal frames extracted by an optical pickup from a constant linear velocity recording type disc.