JPS60241391A - Video disk player - Google Patents

Abstract

PURPOSE:To simplify phase correction of a color burst at jumping of the special reproduction by correcting signals so as to coincide the color bursts in phase when the track number to be jumped is odd. CONSTITUTION:A jumping device is constituted of a jumping pulse generator circuit 11, mirror drive device 12 and mirror 7 in terms of a disk player as shown in the figure. An odd/even number deciding circuit 13 connected to the circuit 11 decides whether the number of the jumping pulses is odd or even, and only when it is odd, the circuit 13 transmits a phase correction signal generation instruction signal to the subsequent phase correction signal generator circuit 14. When the number of the jumping pulses is decided to be even by the previous circuit 13, the circuit 14 will not generate the phase correction signal of the color burst, whereas in case of the odd number, said circuit 14 generates the phase correction signal of the color burst only one time, and supplies it to the drive devive 15 of the next stage.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video disc player capable of still playback, forward or reverse playback, and more particularly relates to a phase correction processing device for color bursts during track jumps. .

2. Description of the Related Art For example, optical video discs and disc players in which NTSC composite video signals (television signals) are recorded in the form of spiral tracks are already known. Also,
Video disk players are already known that are capable of performing still playback and double speed playback, such as double speed or triple speed playback, by jumping the playback light beam.

By the way, the composite video signal of the NTSC system includes a color burst, that is, a color carrier synchronization signal, and the frequency fsc of this color burst is equal to the horizontal synchronization frequency fR15,73426.
3kHz, so fsc is 3.579545 MH
It is said to be z. This color burst has the following two properties.

The phase is inverted every 1111H (horizontal scanning period).

(2) The phase is reversed every frame.

Conventional video disc players are therefore configured to correct the phase of the color burst each time the light beam jumps to an adjacent track. Note that the phase correction is performed by changing the position of the light beam in the time axis direction (disc circumferential direction position) using a time axis error (jitter) correction mirror.

Problems to be Solved by the Invention As mentioned above, in conventional disc players, the phase correction of the color burst is performed every time the light beam jumps to the adjacent track5, which not only complicates the correction operation but also reduces the tolerance. There was a risk that a phase correction error exceeding the range would occur. Although the optical video disc player has been described above, similar problems exist in video disc players that use a signal detector such as a stylus or a capacitive element as a pickup to read signals from the disc. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a video disc player capable of solving the above-mentioned problems.

Means for Solving the Problems To achieve the above object, the present invention reads signals from a video disc on which a composite video signal including color bursts is sequentially recorded in a predetermined track form using a light beam or a signal detector. and a jumping device for jumping the light beam or signal detector from the current track to another track, wherein when the number of tracks to be jumped by the jumping device is an even number, the phase of the color burst is The present invention relates to a video disc player characterized in that it is provided with a device that does not perform correction, but performs correction so that the phases of the color burst match when the number of tracks to be jumped is an odd number.

Effect: In the above invention, phase correction of color burst is not performed when even-numbered tracks are jumped. Even if this is done, no problem occurs because the phase of the color burst of the current track and the phase of the color burst of even-numbered tracks based on the current track match. Since phase correction of the color burst is not performed during the above-mentioned even-numbered track jump, the problem of phase shift of the color burst does not occur.

Embodiment Next, an optical video disc player according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. 1st
In the figure, (1) is a video disk, (2) is a morph for disk rotation, (3) is a laser beam source, and (4) is a morph for disk rotation.
is a beam splitter, (5) is a mirror, (6) is a time axis position correction mirror (tangential mirror), (7
) is a rotating mirror for tracking and jumping, (8
) is a condenser lens, (9) is a beam, αω is a reflected beam detector, αB is a jumping pulse generation circuit, α2 is a drive device for mirror (7), and convergence 3 is an odd or even number of jumping pulses. α4 is a phase correction signal generation circuit, α9 is a driver for the mirror (6), (Ie is a jitter correction signal generation circuit, and αη is a tracking control signal generation circuit.

When the disc player shown in Fig. 1 normally reproduces the composite video signal on disc (1), disc (1) is moved by the motor (
2), the beam (9) generated from the beam source (3) is focused and projected onto the disk (1), and the reflected beam corresponding to the signal is read by the beam detector αQ.

At this time, since the beam (9) does not necessarily scan the track on the disk 11) accurately, the tracking state is detected by a known method, and based on this detection, a tracking control signal is sent from the tracking control signal generation circuit fin. is applied to the mirror drive device, and the position of the beam (9) in the disk radial direction is adjusted by rotating the rotating mirror (7). In addition, since the scanning speed of the beam (9) is not necessarily constant, a jitter correction signal is added from the jitter correction signal generation circuit αQ to the mirror drive device α5)K, and the rotating mirror (
6) By changing the rotation angle K, the position of the beam (9) in the disk circumferential direction, that is, the position in the time axis direction is adjusted. Note that a mechanism (
(not shown) sends a beam (9) in the radial direction of the disk (1) for reproduction.

Incidentally, on the disk (1), a composite video signal of the NTSC system is recorded on a spiral track U as shown in FIG. As explained above, the phase of this color burst is reversed every frame.Therefore, if you switch tracks for still playback or double speed playback, the color burst It is necessary to perform phase correction.

Each frame is recorded on the disk (11) shown in FIG. 2 in such a form that the vertical blanking periods are arranged in a straight line extending in the radial direction of the disk (1).
In the case of the vertical blanking period, when the reproduction beam is scanned from point A to point 0, the beam is jumped from point 0 to point A by 1cI) rack, and the same track is scanned multiple times. Also, when playing at double speed, for example, from point A to B.
Normally scan to the point, then jump from point B to point D, and
Normal scanning is performed from point E to point E, and then a jump is made from point E to point G. Further, in the case of triple speed playback, for example, normal scanning is performed from point A to point B, a jump is made from point B to point F, and then normal scanning is performed from point F to point G. In addition, in the case of 3 borrowing speeds in the reverse direction, for example, after normal scanning from point L to point M, there is a 2 track jump from point M to point H, then normal scanning from point H to point G, and then 0 from point G
Make a two-track jump to the point.

The disk player shown in FIG. 1 includes a jumping pulse generation circuit (111), a mirror drive device (Iz), and a mirror (
7) constitutes a jumping device.

The jumping pulse generating circuit aυ supplies a number of pulses corresponding to the number of tracks to be jumped to the driving device α, and the driving device a2 rotates the mirror (7) to correspond to the jumping pulse, and generates a beam ( 9) in the radial direction of the disk (1). That is, a jumping pulse generating circuit (19) generates a pulse having a voltage amplitude necessary to jump a unit track, and when jumping multiple tracks, a plurality of the above pulses are generated, and the pulse is generated in response to the jumping pulse. The movable mirror aη rotates to switch tracks corresponding to the number of jumping pulses.

The odd/even number discrimination circuit α connected to the jumping pulse generation circuit aυ discriminates whether the number of jumping pulses is an odd number or an even number, and only when the number is odd, the next stage phase correction signal generation circuit (141 The phase correction signal generation circuit (14) sends a phase correction signal generation command signal to the phase correction signal generation circuit (14). It does not generate a signal, but it generates a color burst phase correction signal only once when it is judged to be an odd number.
This is supplied to the next stage drive device α9.

Figure 4 shows the phase correction of color burst.
Figure 4 shows the phase of the color burst of the current track, and Figure 4) shows the phase of the color burst of the adjacent track. As already explained, the phase of the color burst is reversed every frame, so the color burst of 03) and the color burst of 03) have opposite phases. Therefore, the beam is moved from point a on the time axis in Figure 4 (4) to Figure 4 CB).
If you jump to point b on the time axis, the position will be reversed, making normal color reproduction impossible. Therefore, the beam is jumped from point a to point 0 or point d to match the phases of the color bursts.

In the disc player shown in Figure 1, the odd/even discrimination circuit (
131 determines that the number of tracks to jump to is an even number, the color burst phase correction using the mirror (6) is not performed. For example, in the case of 3x speed playback, a jump of 2 tracks is performed, and in the case of 5x speed playback, a jump of 4 tracks is performed in row 5. In these cases, the phase correction of the color burst is not performed and the current track Jump the beam (9) from to another track. That is, the beam (9) is caused to jump without substantially changing the position of the beam (9) in the disk circumferential direction (time axis direction). When jumping an even numbered track, the phase of the color burst of the current track and the even numbered track based on this becomes the same, so there is virtually no problem even if phase correction is not performed.

On the other hand, in the case of still playback, double speed playback, quadruple speed playback, etc., the beam (
9), phase correction of the color burst is required. In this case, the determining circuit (131) determines that the jumping pulse is an odd number, the phase correction signal generating circuit a4 is driven, and the beam (9) is
A control signal for moving from point a in 4) to point 0 or point d in FIG. 4, 03) is generated, and the mirror (6) rotates accordingly. Note that when the number of tracks to be jumped is plural and an odd number, the phase correction of the color burst is not performed every time a unit track is jumped, but is corrected only once. If only one of the odd-numbered tracks is corrected, the number of remaining tracks that are not corrected will be an even number, so as in the case of an even-numbered track jump, there is no need to correct the remaining tracks.

In the disc player of this embodiment, an odd/even discrimination circuit (13) is provided, so that the phase of the color burst is not corrected when jumping an even numbered track, and the phase of the color burst is only once corrected when jumping an odd numbered track. Since the configuration is such that no correction is performed, phase correction of color bursts is simplified.

Modifications The present invention is not limited to the embodiments described above (for example, the following modifications are possible).

Instead of using the mirror (6) for both jitter correction and color burst phase correction, an independent correction mirror may be provided.

ω) The determination between odd and even numbers may not be based on the number of pulses of the jumping pulse generation circuit aυ, but may be determined based on the mode setting operation. That is, in response to the still playback mode and the forward or reverse even multiple speed playback mode setting signal, the phase correction signal generating circuit (141) generates the color burst phase correction f1.fi.
The phase correction signal generating circuit a4 may generate a correction signal so that the phase correction signal generating circuit a4 does not generate a correction signal when the odd number multiple speed reproduction mode is set. Note that in the even number multiple speed reproduction mode, a color burst phase correction signal is generated in synchronization with the first jumping pulse.

(Instead of sending the 0 beam (9) in the radial direction of the disk (1), the disk +1) may be sent in the radial direction.

(2) In order to jump a plurality of tracks, instead of generating a plurality of jumping pulses, a jumping pulse having a voltage amplitude multiple times the pulse for unit track jump may be generated.

(2) Track jumps for double-speed playback may be performed in frame units (at the rate of one round of a track).

[F] It is also applicable when using a disk with concentric tracks. It is also applicable to players that use a needle or the like as a pickup.

Effects of the Invention As is clear from the above, according to the present invention, it is possible to simplify phase correction of a color burst at the time of a jump in special playback.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a disc player according to an embodiment of the present invention, FIG. 2 is a plan view showing the principle of a video disc, FIG. 3 is a waveform diagram showing a part of a composite video signal, and FIG. 4 is a waveform diagram showing a color burst. (1)...Disk, (2)...Motor, (3)...
... Beam source, (6) (force...mirror, αB...
・Jumping pulse generation circuit, (13+...odd number・
Even number discrimination circuit, I... Color burst phase correction signal generation circuit, α9... Mirror drive device. Agent Noriji Takano

Claims (1)

[Claims] (1) A device for reading a signal from a video disc on which a composite video signal including a color burst is recorded in a predetermined track form using a light beam or a signal detector; In a video disc player having a jumping device for jumping a detector from a current track to another track, when the number of tracks to be jumped by the jumping device is an even number, the phase of the color burst is not corrected; A video disc player characterized in that a device is provided for correcting the phases of the color bursts to match when the number of tracks to be jumped is an odd number. (2) The phase of the color burst is corrected when the first track is jumped when odd track tracks are jumped, and is not corrected when the remaining tracks are jumped. A video disc player according to scope 1.