JPS62263789A - Video disk player with picture memory - Google Patents

Abstract

PURPOSE:To eliminate the synchronization turbulence in a monitor screen when a disk reproducing picture and a memory screen (still) are alternately changed over by applying a spidle servo so as to make a reproducing vertical synchronizing signal coincide with a reference phase. CONSTITUTION:The address of a field memory 2 is formed based on the reference vertical synchronizing signal REF-V obtained by dividing the pulses of reference horizontal synchronizing signals REF-H and 2fH formed by a reference oscillator 2 is formed. A reproducing video signal from a disk player main body 1 is applied to a synchronization separating circuit 5, the separated reproducing vertical and horizontal synchronizing signals PB-V, PB-H are supplied to the spindle servo circuit 4, the servo circuit 4 detects the phase difference between the reference REF and the reproducing PB, transmits a spindle motor control signal and controls so as to make the phase of the reproducing synchronizing signal coincide with the phase of the reference synchronizing signal. When a change over switch 3 is changed over from N(normal) to S(still), an R/W signal is changed over to the reading R, and the videosignal is guided out to an output terminal 8 from the memory 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video disc player with an image memory (field memory or frame memory).

[Summary of the invention]

When the spindle servo is applied so that the vertical synchronization signal of the disc playback video signal and the reference synchronization signal are in phase, and the disc playback and image memory (1 field or 1 frame) reading (still image) are alternately switched. This is a video disc player that prevents the synchronization of the monitor screen from occurring.

[Conventional technology]

When performing CAV (constant angular velocity) playback on a video disc player, still playback is possible because the vertical synchronization signals are aligned at fixed positions on the CAV recorded disc. However, when performing reproduction at CLV C (constant linear velocity), still reproduction is difficult because the vertical synchronization signal on the disk is not at a fixed position (does not correspond to the -period field).

Therefore, an image memory for one field or one frame is provided, and data is written to the memory during CLV playback (
However, it is conceivable to read the field or frame image data from the memory and display it as a still image when there is a still or pause operation.

[Problem that the invention seeks to solve]

Writing to the image memory is performed in synchronization with the vertical synchronization signal in the reproduced video signal, while reading from the image memory is performed in synchronization with the 6011z reference signal obtained from the reference oscillator. Therefore, when switching from memory playback (still) to disk playback (normal) or from disk playback to memory playback, the monitor image is temporarily disturbed. In other words, the phases of the vertical synchronization signals of the still video signal and the CLV playback signal obtained from the disc are unrelated to each other, and during still recording, the pickup repeatedly scans the same part of the disc while jumping several trunks. This is because the phase of the reproduced vertical synchronization signal varies with each jump. The image synchronization disturbance continues until the vertical oscillation section of the monitor receiver follows the shifted vertical synchronization.

It is an object of the present invention to solve this problem and to prevent monitor synchronization from occurring when switching still playback and normal playback alternately.

[Means for solving problems]

As shown in FIG. 1, the video disc player with an image memory of the present invention has an image memory 2 into which one field or one frame of a playback video signal is written when playing a disc.
, a changeover switch 3 that switches from the disc playback video signal to the memory read video signal during still playback, and a synchronization generation circuit (reference oscillator 6.11525 frequency divider) that synchronizes the readout of the image memory with the reference vertical synchronization signal REF-V. 7) and the playback vertical synchronization signal PB- from the disk 11.
The spindle servo circuit 4 controls the disk rotation phase so that the phases of V and the reference vertical synchronization signal REF-V coincide with each other.

[For production]

On the disk playback side (CLV playback) during still operation (memory read), track jumps occur periodically to scan a constant diameter, making the playback vertical synchronization discontinuous, but the spindle servo immediately brings the disc back to the reference phase. Therefore, when switching between memory images and disc playback images (still/
There is no monitor disturbance at all when switching from normal to normal.

〔Example〕

FIG. 1 is a block diagram of main parts of a video disc player showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a player body, which includes a reproduction processing circuit section, a spindle drive section, a pink amplifier, and the like.

A reproduced video signal obtained from the disc player main body 1 is led out to an output terminal 8 via a changeover switch 3. Furthermore, the reproduced video signal is also given to the field memory 2 at the same time, and the reproduced video signal is updated (continuously) one after another and written.

A read/write command R/W for the memory 2 is given from the main body 1. In this embodiment, the address of the memory 2 is the reference horizontal synchronizing signal REF-H generated by the reference oscillator 6 and 2fH (twice the horizontal frequency) obtained from this oscillator 6.
The reference vertical synchronizing signal REF-V obtained by frequency-dividing the pulse of 11525 by the 11525 frequency divider 7 is generated in the address generation section in the memory 2. As will be described later, these standards REF-H and REF-V are in phase with the vertical and horizontal synchronizing signals of the reproduced video signal from the disk. Therefore, there is no need to create an address in phase synchronization with a reproduction synchronization signal as in the prior art, and a PLL circuit or the like for this purpose can be omitted.

When a still or pause operation is performed, the changeover switch 3 is switched from N (normal) to S (still) in response to a changeover signal. At the same time, the R/W signal becomes readout (R),
The video signal for one field stored in the field memory 2 is converted into an analog signal and output from the changeover switch 3 to the output terminal 8. Since the synchronization signals of the reproduced video signal from the disk player 1 and the read video signal of the memory 2 are in phase, no synchronization disturbance occurs on the monitor screen.

Similarly, no synchronization disturbance occurs when switching from a still screen to normal playback.

As shown in FIG. 1, the reproduced video signal from the disc player main body 1 is given to the synchronization separation circuit 5, and the separated reproduction vertical and horizontal synchronization signals PB-■ and PB-H are supplied to the spindle servo circuit 4. be done. On the other hand, the previously mentioned reference vertical and horizontal synchronization signals REF-V and REF-H are also applied to the spindle servo circuit 4.

This servo circuit 4, as shown in the main circuit diagram of FIG.
Regarding each vertical and horizontal synchronization signal, the phase difference between the reference REF and the reproduction PB is detected by a phase detector 12.13, and each phase difference signal is added by an adder 14 to derive a control signal for the spindle motor. . Since this control signal is given to the spindle motor drive section of the player main body 1, a servo loop is formed and the control signal is controlled so that the phases of the playback vertical and horizontal synchronization signals and the reference vertical and horizontal synchronization signals are different from each other. will be held.

On the other hand, as shown in the disk plan view of FIG. 3, during still operation, the pickup scans the track 11, jumps several tracks at regular intervals, and traces approximately the same portion. As shown in the time charts of FIGS. 4A and 4B, the reference vertical synchronizing signal REF-
Since the phases of V and the reproduction vertical synchronizing signal PB-V are matched by the spindle servo, no synchronization disturbance occurs when switching from disk reproduction to memory read (still). When a track jump is performed, the phase of the reproduced vertical synchronizing signal PB-V changes discontinuously, as shown in FIG. 4B, and deviates from the reference REF-V.

However, since the spindle servo is working, the phase shift is corrected. Therefore, even when switching from memory reading to disc playback, monitor synchronization will not be disrupted.

Incidentally, the spindle servo may be performed based on the reference frame pulse and the reproduction frame signal 2. Also CAV
The spindle servo shown in FIG. 1 may also be in operation during the reproduction mode.

〔Effect of the invention〕

As described above, in the present invention, since the spindle servo is applied so that the reproduction vertical synchronization signal matches the reference phase, in the CLV reproduction mode, the disc reproduction image and the memory screen (still)
There is no synchronization disturbance on the monitor screen when switching alternately.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the main parts of a video disc player to which the present invention is applied, Fig. 2 is a block diagram of the spindle servo circuit of Fig. 1, Fig. 3 is a schematic plan view of the video disc, and Fig. 4 is the operation. This is a time chart. In addition, in the symbols used in the drawings, 1-------------111-- Video disc player main body 2------------ Field memory 3 −・−・−・・−・−Switching switch 4−−−−−−−−−・−1−−−・−・−Spindle servo circuit 5・−・−・−1−−−−−・− Synchronous separation circuit 6---------Reference oscillator 7---1-
−−−−・−−11−− Frequency divider 8−−−−−−−−−−
------1 output terminal 10-----111----
--Disk 11--Track 12.13--11--Phase detector 14-.
...----- It is an adder.

Claims (1)

[Claims] An image memory into which one field or one frame of a playback video signal is written during disk playback, a changeover switch that switches from the disk playback video signal to a memory readout video signal during still playback, and a switch that synchronizes the readout of the image memory with a reference vertical synchronization signal. 1. A video disc player with an image memory, comprising: a synchronization generation circuit for the reproduction of a vertical synchronization signal from the disc; and a spindle servo circuit for controlling a disc rotational phase so that the reproduction vertical synchronization signal from the disc and the reference vertical synchronization signal match in phase.