JPS6262673A - Video disk reproducing device - Google Patents

Abstract

PURPOSE:To reproduce a still picture by repetitively reproducing a track of one frame in which a vertical synchronous signal is recorded by making coincide with the displacement direction of an optical pickup nearly near to an innermost periphery in a reproducing device of a video disk on which a video signal is recorded at CLV (constant linear velocity). CONSTITUTION:To a vertical synchronous signal 10 of A field situated at an innermost periphery, vertical synchronous signals 11, 12 of B, C fields are respectively recorded at nearly coinciding positions in the direction of a diameter of a video disk 1. When a still picture reproducing operation is designated by a function key 8, a control signal is supplied from a system controller 7 to start the still picture reproducing operation and under the condition to which various types of servos are applied, the A and B fields are reproduced. When an optical pickup 3 reaches to a position of the vertical synchronous signal 12 of the C field, the optical pickup 3 is returned to a start end position of the innermost track by a thread servo signal from a servo circuit 5. The first frame consisting of the A and B fields is reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a reproducing apparatus for a video disc rotated at CLV (constant linear velocity).

[1 Summary of the Invention] The present invention provides a reproducing device for a video disc on which a video signal is recorded using CLV, in which a vertical same word is recorded approximately in the direction of displacement of an optical pickup in the vicinity of the innermost [4]. By repeatedly reproducing a track of one frame, it is possible to reproduce a still image.

[Conventional technology]

On conventional video discs, audio and video information is recorded in a spiral manner at CAV (constant angular velocity), and vertical synchronization signals are arranged in a line in the radial direction of the video disc. Therefore, variable speed modes such as still replay, step playback, triple speed playback, etc. can be easily performed.

However, in the case of CAV recording, since the angular velocity is constant and the rotational speed is high on the outer circumference side, the recording density becomes lower towards the outer circumference side (there is a drawback that the recordable capacity of the video disc cannot be used effectively).

Therefore, a long-duration type CLV video disc has been proposed that records FM-modulated video signals at CLV (constant linear velocity) to maintain a constant recording density, and records data to the full extent of the recordable capacity of the video disc. There is.

[Problem that the invention seeks to solve]

However, in the case of CLV video discs, since recording is performed at a constant linear velocity, the recording position of the vertical synchronization signal almost never coincides in the radial direction of the video disc, making it impossible to play back still images. Met. Furthermore, since still images cannot be played back, it is difficult to start synchronized video disc players when using a plurality of video disc players at the same time.

Therefore, it is an object of the present invention to provide a video disc reproducing apparatus that can reproduce still images even when reproducing CL and V video discs.

[Means for Solving the Problems] The present invention provides a method for reproducing still images by repeatedly reproducing a track for one frame near the innermost circumference in a reproducing device for a video disc on which a video signal is recorded at a constant linear velocity. This is a video disc playback device that is unique in that it allows for.

[Effect]

When the CLV video disc 1 is loaded and the variable speed playback mode is entered by inputting the function key 8, the innermost track whose vertical synchronization signals are aligned approximately in the radial direction of the video disc, for example, is searched. Then, the first frame located at the innermost circumference is repeatedly played back, resulting in a still image playback state.

〔Example〕

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

FIG. 1 shows the configuration of a video disc reproducing apparatus to which the present invention is applied. In FIG. 1, the symbol l is a video disc.

For example, the video disc 1 may contain, for example,
A narrow pinch audio and video information track with a track width of 1.67 μm is formed in a spiral shape at CLV (constant linear velocity).

Figure 2 shows tracks near the innermost circumference of the video disc 1 recorded in CLV. In Figure 2, the black dots are located at the beginning of one field's worth of audio and video information. This is a vertical synchronization signal.

As shown in FIG. 2, the vertical synchronizing signal 11 of the B field is recorded at a position approximately coincident with the vertical synchronizing signal 10 of the A field located at the innermost circumference in the radial direction of the video disc 1, and the C field The vertical synchronizing signal 12 of the A field is recorded at a position that substantially coincides with the vertical synchronizing signal 10 of the A field in the radial direction of the video disc.

Also, in FIG. 1, 3 is an optical pickup. The optical pickup 3 incorporates optical components such as a laser diode and an objective lens.
Focus error detection circuit.

A tracking error detection circuit, an RF circuit, etc. are provided. Further, the optical pickup 3 is configured to be displaced in the radial direction of the video disc 1 by a feed motor 4.

A video disc 1 is loaded on a turntable attached to the shaft of a spindle motor 2, and the spindle motor 2
The axial center of the video disc l is held in such a state that the center of the video disc l coincides with the center of the video disc l.

When the function key 8 is operated and the playback key is pressed, a start signal is supplied to the system controller 7. Is there a restriction on making it playable in the system controller 7? II signal is generated and this control signal is supplied to the servo circuit 5. Further, a control signal is supplied from the system controller 7 to the signal processing circuit 6.

The servo circuit 5 starts operating in response to the control signal, and the servo circuit 5 supplies a spindle servo signal to the spindle motor 2, and the servo circuit 5 supplies a thread servo signal to the feed motor 4.

Spindle motor 2 starts rotating by spindle servo k, and video disk 1 rotates.

Further, the feed motor 4 is activated by the thread servo signal, and the optical pickup 3 is moved to a predetermined starting position of the innermost track. A focus error signal and a tracking error signal are supplied from the optical pickup 3 to the servo circuit 5. A focus/tracking servo signal is supplied from the servo circuit 5 to the optical pickup 3, and the distance between the objective lens of the optical pickup 3 and the video disc 1 is controlled to be a predetermined distance, and accurate tracking is performed. controlled.

Further, the spindle motor 2 is provided with a rotation detection circuit, and a detection signal indicating the rotation speed and rotation phase is supplied from the rotation detection circuit to the servo circuit 5. Servo circuit 5
By this operation, the rotation speed is controlled to be, for example, 180 Or p m on the innermost track of the video disc 1.

The reproduced signal read by the optical pickup 3 is an RF
The signal is supplied to the signal processing circuit 6 via the circuit. In the signal processing circuit 6, the reproduction signal is FM modulated to obtain a reproduction video signal, a reproduction synchronization signal is extracted from this reproduction video signal, and this reproduction synchronization signal is supplied to the servo circuit 5. The servo circuit 5 controls the rotation of the spindle motor 2 so that the interval between reproduction synchronization signals is constant.

When the normal playback operation is designated by the function key 8, the normal playback operation is started, the feed motor 4 is controlled by the thread servo signal, and the optical pickup 3 is displaced in the outer circumferential direction.

When playing back the video disc 1, the track king servo corrects minute track deviations, and the focus servo maintains a constant distance between the video disc 1 and the objective lens. A reproduced signal read from the video disc 1 is supplied to a signal processing circuit 6, and an audio signal and a video signal are taken out to an output terminal 6a.

Furthermore, when a still image playback operation is designated by the function key 8, a control signal is supplied from the system controller 7 to start the still image playback operation, and the second A shown in the figure
field and B field are played back, and the first frame is played back repeatedly. In other words, when the optical pickup 3 reaches the position of the vertical synchronization signal 12 of the C field, the thread servo signal from the servo circuit 5 causes the optical pickup to
7 cup 3 is returned to the starting position of the innermost track.

The first frame consisting of the A field and B field is played back again. During still image playback, a still image video signal in which the first frame is continuous is output to the output terminal 6a of the signal processing circuit 6.

The operation of the system controller 7 will be further explained in detail with reference to the flowchart shown in FIG.

When the playback key of the function key 8 is turned on (step ■), the process proceeds to step ■, and in step ■ it is determined whether the variable speed playback key has been pressed. If the variable speed playback key is pressed, the process moves to step (3).

Further, if the variable speed playback key is not pressed, a transition is made to the normal playback operation state (step 2).

In step (2), it is determined whether the disc is a CLV video disc. If it is a CLV video disc, the process moves to step (2). Further, in the case of a CAV video disc instead of a CLV video disc, the process shifts to a variable speed playback operation, for example, a still image playback operation (step 2).

In step (2), a track near the innermost circumference, for example, a track located at the innermost circumference, is searched.

Then, the still reproduction of the first frame is performed (step ■), and the process moves to steps ■ and ■.

In step (2), it is determined whether the playback key has been pressed again, and in step (2), it is determined whether or not the stop key has been pressed. If the playback key is pressed, the process moves to step (3) and normal playback operation starts. Furthermore, when the stop key is pressed, the playback operation is ended.

If neither the play key nor the stop key is pressed, the process returns to step ■ and the first frame is played again, and the first frame is repeatedly played until either the play key or the stop key is pressed. and enters the still image playback state.

In one embodiment of the present invention, a configuration has been described in which the first frame located at the innermost circumference is repeatedly reproduced to create a still image reproduction state, but regarding other frames located near the innermost circumference, It is also possible to enter a still image playback state.

〔Effect of the invention〕

In this invention, when a CLV video disc is loaded and the variable speed playback mode is set, the innermost track where the vertical synchronization signals are arranged approximately in the radial direction of the video disc, for example, is searched, and the most The first frame located on the inner circumference is repeatedly reproduced.

Therefore, according to the present invention, even when playing back a CLV video disc, stills can be played back. Further, since the first frame on the innermost circumference can be set to a still image playback state, it is easy to start a plurality of video disc players in synchronization.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a route diagram of a video truck used to explain the operation of an embodiment of the invention, and Fig. 3 is used to explain the operation of an embodiment of the invention. It is a flowchart. Explanation of main symbols in the drawings 1: Video disk, 2 Nissin spindle motor, 3:
Optical pickup, 4: Feed motor, 5: Servo circuit, 6: Signal processing circuit, 7: System controller, 8: Function key. Agent Patent Attorney Tadashi Sugiura Figure 1 Section Left〒゛Isugu no Tora 1. Figure 2: Flow rate of 1,000 meters Figure 3

Claims (1)

[Scope of Claims] A playback device for a video disc on which video signals are recorded at a constant linear velocity, characterized in that still images can be played back by repeatedly playing back one frame of track near the innermost circumference. video disc playback device.