JPS63102575A - Video disk player - Google Patents

Abstract

PURPOSE:To prevent the disorder of a time base due to the discontinuity of the horizontal synchronizing signal of a reproducing video signal written into a memory after the track is jumped by controlling the rotation of a disk so as to coincide the phase of the horizontal synchronizing signal and a reference signal in a reproducing video signal. CONSTITUTION:A reproducing video signal N obtained by a pick-up 2 is inputted to a horizontal synchronizing separating circuit 16, only a horizontal synchronizing signal Hsync is extracted, the phase comparing with a reference signal from a reference signal generating circuit 18 is executed by a phase comparing circuit 17 and a phase error signal equivalent to the phase difference is supplied to a spindle motor servo circuit 19. While the discontinuity of the Hsync of the reproducing video signal occurs immediately after the track jumping after a kicking pulse (a) occurs, a detecting signal (f) is not supplied to a writing control circuit 11 as a writing command signal (h), writing is executed only when the time base control is normal, and the static image signal comes to be the picture in which the Hsync is continuous and stable.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to the special playback of a video disc player in which a video signal is recorded at a constant linear velocity. is recorded at a constant angular velocity of 2 fields per trunk rotation, and mcAV
Disk and CLV recorded so that the linear velocity is constant
There is a disc.

On CAV discs, synchronization signals are recorded in a line in the radial direction, so even if the pickup that scans the disc jumps tracks in the radial direction, fluctuations in the time axis due to discontinuous flow of horizontal synchronization signals will not occur. This is a well-known fact that allows special reproduction of stills and the like.

-7. Since the synchronization signals in the radial direction are not lined up in a line on the CLV disk, the reproduction synchronization number 1 is discontinuous before and after the track jump. In addition, the rotational speed of a given disc is different, and the time limit is greatly disturbed, and the playback output screen ζ color distortion, vertical synchronization disturbance, horizontal skew, etc. occur, and special playback (difficult) occurs. Japanese Unexamined Patent Publication No. 58-159577 (HD4N5
It is conceivable to store a predetermined one-frame signal in another memory means, and to manipulate and output the signal from the memory means during special playback on a CLV disc, as shown in the prior art in No. 1999/93).

(C) Points to be Solved by the Invention As shown in the above-mentioned prior art, special reproduction is possible even on CLV discs by recording one screen worth of reproduced video signals in a memory means. However, when writing the playback video signal to the memory means, if a discontinuity occurs in the horizontal synchronization signal immediately after a track jump, the playback video signal will be written in a state where the time axis control is disrupted, and this will result in a complete failure. If it is read out, the screen will be distorted and stable special playback will not be possible.In the prior art ζ, during this time point J? There is no suggestion of a solution.

2) Means for solving the 0-point problem The present invention provides a pickup in which a disk on which an imaging signal is recorded at a constant linear velocity is scanned over the entire disk and a track jump is performed during special playback, and this pickup has nine techniques. A memory means for storing one screen of the reproduced video signal as a full still image signal, a phase comparison stage for comparing the phases of the horizontal synchronization signal in the reproduced video signal and the reference signal, and rotation of the disk so that the phases match. ? □ (E) characterized by comprising: a rotation control means for controlling; and a write control means for prohibiting writing of the reproduced video signal into the memory means when the phase difference between the horizontal synchronization signal and the reference signal exceeds a predetermined value. Operation Since the present invention is constructed as described above, even when a track jump is performed on a CLV disc, a reproduced video signal with normal time axis control is written into the memory means.

(F) Example Hereinafter, one embodiment of the present invention will be explained according to the drawings. □ Fig. 1 shows the circuit diagram of the system of this embodiment, and Fig. 2 shows a timing chart. Explaining % high-speed playback during special playback. During high-speed playback, C
Pickup +2+ by scanning LV disk tl+
The reproduced video signal (N) obtained is synchronously separated in the vertical synchronous separation circuit 13;
s'yJ1C) (C)' iM counts and output) In other words, for each MVsylc, the system controller (
3; Yoli kick pulse (a) is emitted. In this embodiment, the case of 1n-7 is explained.

This kick pulse (a) i is composed of a pickup drive circuit (input to 41 □ this pickup drive circuit + 41i tracking 1 @ circuit/AMP), and the kick pulse (a) is composed of a tracking coil! After being amplified through a control circuit and applied to a tracking coil, a pickup +21 track jump is performed.

With this kick pulse (a), the R-8 flip-flop 15+, whose Q output is the reset input of the Vsync counter +61, issues a reset 1 signal (b).
The reset of Vsync (C) is released and the count of Vsync (C) starts □ When the vsync counter f61i (M -2) counts, its output is set to shift from L level to H level □ Kick pulse ta) After i birth, Vsy
When nc (C) is counted CM-2), Vsy
nc counter (6-count pulse (d) is emitted, and this count pulse (d) is R-8FF +71'i -
i = , 1, R-8FF171rzVsync
(C) The total delay circuit (8) delays the signal for a certain period of time (1) and resets it with a constant signal (C), and falls as the output i(e). Note that delay time (t) after i track jump, from CM-2)th vsync to (M-1)ff
! The writing start point is set between the l-th Vsync, and usually the number H (H
0 set before the horizontal scanning period) The falling detection circuit (81 detects this falling vt- and outputs the detection signal (f)i. This detection signal (f) 1'! gate circuit ( The reproduced video signal (N
)'s write control circuit (1'') becomes the -it inversion command signal (h) to the write control circuit (IO).
A start signal including 21Vc-iI* is issued, and the reproduced video signal obtained from the pickup +21 (N11 field (
The A/D conversion circuit [111] converts the t signal k3fsC(fs
Reading from the video RAM (121) is continuously and repeatedly performed using a read timing signal having a sampling frequency of 3 fSC. □However, the read tying signal ζ
It is independent of the write start signal, and the video RAM (121) can be accessed at high speed, and while one field of the playback video signal is being written, it is also possible to read from the video RAM n21 at the same time. The read still image signal is converted to L at the D/A conversion circuit (131).
l/Al/It is displayed on the monitor (1 screen).

Next, the gate circuit (91) which controls the passage of the detection signal (f)'i write command signal <h> will be explained.

The reproduced video signal (N) obtained from the pickup (21) is input to the horizontal synchronization separation circuit (161, where only the horizontal synchronization signal < Hsync) is extracted, and the phase comparison circuit (phase comparison means) α7) generates a reference signal. circuit! A phase comparison is made with the reference signal from 1&.

A phase error signal ζ corresponding to the phase difference between the two signals obtained by this phase comparison is supplied to the spindle motor servo circuit (rotation control means) (19), thereby controlling the servo of the spindle motor (not shown) that completely drives the rotation of the disk III. That is, Hsync is rotated so that it matches the phase of the reference signal, and vlI@ is changed.In addition, the reference signal generation circuit (18) is composed of a fixed oscillator and a frequency dividing circuit, A phase error signal (a) which constantly generates pulses having the frequency of a regular horizontal synchronization signal is also supplied to the lock detection circuit (2).If the phase error signal is within a predetermined level range, the lock detection circuit (c1g) receives If the phase matches (phase lock) with the reference signal, the Te5C lock signal (g) is emitted. □The Goo 8 circuit +91 outputs the detection signal (f') only when the TBG lock signal (g) is at H level. Passage is allowed, and when it is at L level, passage is blocked.
Immediately after the track jump after the kick pulse (a) is generated, the detection signal (f) is supplied to the write control circuit 111- as a write command signal (h) during a period in which the Hsync discontinuity of the reproduced video signal is occurring. Therefore, writing of the reproduced video signal (N) to the video flAM+121 is prohibited, and writing is performed only when the time field control is normal, and the still image signal becomes stable with continuous Hsync and becomes the t screen □ As mentioned above. Separately from the embodiment shown in FIG. 1, the kick pulse (a) from the system controller 1; does not have a constant cycle, but after the kick pulse (?L) is generated, if the TBG lock signal (g+) is output, the write typing signal is immediately output. However, it is also possible to configure the system controller 13+j to output the next kick pulse once the writing is completed.However, when transitioning from normal playback to special playback, first write the kick pulse before the kick pulse is generated. The configuration is such that the kick pulse is emitted after this writing is completed.

In this embodiment, high-speed playback will be explained, and by selecting the value of t and M and the number of tracks to jump to, special playback such as slow speed playback becomes possible.

(g) Effects of the Invention As described above, according to the present invention, when all still image signals are stored in a memory and used for special playback of a CLV disc, the horizontal synchronization signal of the reproduced video signal written to the memory after a track jump is not affected. Disturbance of the time axis due to continuity can be prevented, and a stable [7 special playback screen] can be obtained.

[Brief explanation of the drawing]

The drawings all relate to the present invention, and FIG. 1 is a circuit block diagram, and FIG. 2 is a timing chart. Mouth 2...Video FtAM
(memory means), Ding...phase comparison circuit (phase comparison means), (HJ...spindle motor servo circuit (rotation control means).

Claims (1)

[Claims] (1) A disk on which a video signal is recorded at a constant linear velocity,
a pickup that scans the disk and makes track jumps during special playback; a memory means into which one screen of the reproduced video signal obtained by the pickup is written as a still image signal; and a horizontal synchronization signal in the reproduced video signal. a phase comparison means for comparing the phase with a reference signal; a rotation control means for controlling rotation of the disk so that the phases match; and a phase difference between the horizontal synchronization signal and the reference signal by the phase comparison means. a video disc player comprising write inhibiting means for inhibiting writing of the reproduced video signal to the memory means when a predetermined value is exceeded.