JPS6165582A - Recording disc playback device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording disc reproducing apparatus such as a video disc, and particularly to a recording disc reproducing apparatus for detecting and reproducing an information signal on a recording disc using a signal detecting means. The present invention relates to a device having a time axis variation component correcting device for correcting an axis variation component.

Conventional configurations and their problems In recording discs such as video discs, imperfections in the central axis of the recording disc, local distortion of warp 1, or mechanical tolerances in the central axis occur when double-sided pressing is performed. . When such a recording disk is reproduced, the reproduced signal includes time axis fluctuations. For this reason, when the reproduced signal includes a video signal, when the video signal including this time axis variation is reproduced on a television receiver, horizontal shaking of the screen may occur, significantly degrading the quality. Therefore, it is one type of video disc. In the VHD system, the time axis fluctuation component is corrected by the control system shown in FIG. (10) is a recording disk; (11) is a signal detection means for detecting information signals from the recording disk (lO), which corresponds to the playback needle in the VHD system; (IIA) is a signal detection means (11) attached to one end; It is a cantilever with a permanent magnet (11B) attached to the other end. The permanent magnet (IIB) is surrounded by a time axis variation component correction coil (IIG) and a radial direction driving coil (LID). Time axis fluctuation component correction signal by electromagnetic induction-3
(old) according to the time axis fluctuation component correction coil (]IIG
is applied to attract or repel the permanent magnet mB), and the signal detection means (11
) is moved in the tangential direction of the track of the information signal, and the signal detection means (11) is moved in the radial direction by acting on the radial drive coil (110). (
12) is the signal (31) detected by the signal detection means (11).
) is a reproduced horizontal synchronizing signal separation unit that separates the reproduced horizontal synchronizing signal (32) from the reproduced horizontal synchronizing signal (32). (13) is a reference signal generation section,
Generate a reference horizontal synchronization signal (33) as shown in Figure 2,
Based on this reference horizontal synchronization signal (33), the trapezoidal wave generator (1
4) generates a trapezoidal wave signal (34). The rising slope of this trapezoidal wave signal (34) is used to convert the 1-time axis, in other words, the phase, into a voltage. Using this trapezoidal wave signal (34) and the reproduced horizontal synchronization signal (32),
In the sample hold section (15), the reproduced horizontal synchronization signal (
32) is held by the rising slope of the trapezoidal wave signal (34) as shown in the waveform (35). The held signal is converted into the form shown in the waveform (36) by the integrating section (17).

The signal level of the waveform (36) is the same as the next reproduction horizontal synchronization signal (3
2) until it is input to the sample hold section (15).
are maintained at approximately the same level. As mentioned above, since the phase is converted to voltage, the voltage fluctuation of the output signal waveform (36) of the integrating section (16) is due to the phase difference between the reference horizontal synchronization signal (33) and the reproduced horizontal synchronization signal (32). 6 indicates the amount of change, that is, the time shift (time axis variation) of the reproduced horizontal synchronization signal (32) with respect to the reference horizontal synchronization signal (33).

The output signal waveform (36) of the integrating section (16) is applied to the coil (tic) for 1 time axis fluctuation acid content correction via the tangential direction signal detection means drive section (17),
) in the tangential direction of the track of the information signal on the signal detection means (
11) to move the recording disk (
10) to reduce the time axis fluctuation component in the reproduced signal.

By the way, there is a function called special playback in means of playing back recording discs such as video discs. For example, the signal detecting means (11) is forced to be at a predetermined position (AO) (A1) so that the scanning locus of the signal detecting means (11) shown in the thick line indicates the track of the information signal indicated by the thin line in FIG. The information signal is moved by A2 to the adjacent information signal track, and the information signal is detected and reproduced intermittently. With this function, first, it is possible to quickly search for a desired portion while viewing the playback screen. Second, unlike the case where all information signals such as video signals are reproduced continuously, it is possible to realize a playback screen with fast or slow movement in the forward or reverse direction, or a static playback screen, which makes it possible to achieve high performance in recording disk playback devices. In order not to degrade the quality of the playback screen even during special playback that can add value, time axis variation component correction control is performed as described above.
The figure shows a block diagram of a typical conventional VHD player that performs special playback and time axis variation component correction. (
18) is during special playback of the recording disc (lO) in the control section, for example in FIG. (A,
) or at position B (work A), the signal detection means (1
A kick pulse (37) and a damping pulse (38) for forcibly moving the information signal track on the inner circumference of the recording disk (10) adjacent to each other in the radial direction are output. The signal detection means (11) acts on the radial drive coil (LID) via the section (19).
to move in the radial direction. The kick pulse (37) and the damping pulse (38) have waveforms as shown, for example, in FIG.
) is forcibly moved inward, and the damping pulse (38) is the kick pulse (37).
It has a function of acting on the signal detecting means (11) with the opposite energy to set the signal detecting means (11) on the track of a desired information signal. The signal detection means (11) detects the damping pulse (3) from the start of generation of the kick pulse (37).
8), that is, the section (A) [section (A2) in FIG. 3] moves between the tracks of the information signal.

In the case of conventional special playback, there have been problems such as the fifth order. That is, even when the signal detection means (11) moves between tracks of the information signal, the reproduction horizontal synchronization signal (32) is used to perform time axis fluctuation component correction control in the same way as while scanning the tracks of the information signal. I do. However, since no information signal including a horizontal synchronization signal is recorded between the tracks of the information signal, the waveform of the reproduced horizontal synchronization signal (32) is either completely missing, as shown in FIG. 6, or has noise-like irregularities. It may be an accurate signal. The integration section output signal (36) using such a signal becomes an abnormal signal, which is detected by the signal detection means (
11), the signal may move extremely unstable in the tangential direction, causing abnormal horizontal shaking of the playback screen or causing damage to the signal detection means (11) to the recording disk (10). This is the current situation.

OBJECTS OF THE INVENTION The present invention provides a recording method that takes protective measures for time axis fluctuation component correction control when a signal detection means moves between tracks of an information signal during special playback, thereby eliminating the problems encountered in the conventional example. The purpose is to provide a disc playback device.

Structure of the Invention The recording disk reproducing apparatus of the present invention includes a signal detecting means for detecting an information signal recorded in a spiral or concentric manner on a disk-shaped recording medium, and a signal detecting means for detecting an information signal recorded on a disk-shaped recording medium in an adjacent track or a plurality of tracks. Forcible transfer means for forcibly moving the information signal to a distant track, and a control signal responsive to a time axis fluctuation component of the reproduced signal detected by the signal detection means.

and a correction means for reducing the time axis fluctuation component by applying the current to the signal detection means, and while the signal detection means is being forcibly moved by the forced transfer means, the correction means applies the signal to the signal detection means according to the time axis fluctuation component of the reproduced signal. The present invention is characterized in that the control signal is replaced with a value that is substantially the same as the median value of the change range, and the time axis fluctuation component correction control is interrupted.

Further, the recording disk reproducing apparatus of the present invention is characterized in that, during forced movement by the forced phase means, the signal detection means is held at substantially the same value as the value immediately before the forced movement.

Description of examples Hereinafter, the present invention will be explained based on examples.

FIG. 7 shows the configuration of the first invention, which protects the time axis variation component correction control during special playback. Components having the same functions as those in FIG. 4 are given the same reference numerals and their explanations will be omitted.

The switching unit (20) receives kick pulses (37) and damping pulses (38) from the control unit (18) as shown in FIG.
During the output section of , that is, when the signal detection means (11) receives the time axis fluctuation component correction pulse (39) output while moving between tracks of the information signal, the sample and hold unit input signal (
, 42), the input of the reproduced horizontal synchronizing signal (32) to the sample hold section (15) is cut.

During the period in which the input of the reproduced horizontal synchronizing signal (32) is cut, the output signal (36) of the integrating section (16) is maintained at almost the same value as just before the reproduced horizontal synchronizing signal (32) is cut. become. That is, 1 time axis fluctuation acid content correction pulse (3
9) is signaled, the output signal (36) of the integrating section (16) is held almost the same as the value immediately before the output of the time-axis variation component correction pulse (39), thereby correcting the 1-time-axis variation acid content. control continues.

Next, when the output of the time axis fluctuation component correction pulse (39) is completed, the reproduction horizontal synchronization signal (32) is input to the sample hold section (15), and the output signal (36) of the integration section (16) is input as before. ) changes according to the time axis fluctuation component of the reproduced horizontal synchronization signal (32).

FIG. 9 shows the second aspect of the present invention. In FIG. 9, a switching section (21) is added to provide the following functions. When the switching unit (21) receives the time-axis variation component correction pulse (39), the switching unit (21) switches the signal detection unit (
The output signal (36) of the integrating section (16) input to the section (17) is cut, and the output signal (36) of the integrating section (16) is used as a replacement signal.
A signal having a level (R/2) approximately at the center value of the change range R of 36) is generated and output. That is, the time axis fluctuation component correction control is temporarily interrupted.

Next, when the output of the time axis fluctuation component correction pulse (39) is finished, the output signal (36) of the integrating section (16) is
is outputted to the signal detection means driving section (17) as an output signal (40) of the switching section (21), and time axis fluctuation component correction control is performed again.

In the above embodiment, the signal detection means (1) is moved to an adjacent information signal track, but signal detection is also performed when the signal detection means (11) is moved to an information signal track several tracks apart. When the means moves between tracks of the information signal or momentarily crosses the track of the information signal, the detection of the reproduced horizontal periodic signal tends to be inaccurate, so if the above control is applied, the time axis fluctuation can be avoided without any problem. Component correction control can be performed. Furthermore, the present invention can be implemented using a signal capable of detecting time axis fluctuations of other detection signals without using the reproduced horizontal periodic signal. The point is, the section where the signal detection means is forcibly moving, ie.

When the detection signal is likely to be inaccurate, the control shown in this embodiment may be performed to stabilize the one-time axis fluctuation acid content correction control.

Effects of the Invention The recording disk reproducing apparatus of the present invention, while the signal detection means is being forcibly transferred by the forced transfer means, controls the control signal according to the time axis variation of the reproduced signal at a value that is almost the same as the median value of the change range. The time axis fluctuation correction control is then interrupted, or the signal detection means is held at almost the same value as the value immediately before being forcibly moved, so that the following effects can be obtained.

While the signal detection means is being forcibly moved, that is, the reproduced horizontal synchronization signal (
32) The reproduction horizontal synchronization signal (
32), the time axis fluctuation component correction control is not performed.
Inaccurate reproduction horizontal synchronization signal (3
The adverse effects caused by 2) as in the conventional example no longer occur, and stable time axis fluctuation component correction control can be performed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a time axis fluctuation component correction device in a conventional recording disc playback device, Fig. 2 is a waveform diagram of the main part of Fig. 1, and Fig. 3 is an explanatory diagram of scanning of the signal detection means during special playback. , 4th
The figure shows the configuration of a conventional time axis fluctuation component correction device and special regeneration control device, Figure 5 is a waveform diagram of the hacking pulse and damping pulse, Figure 6 is a waveform diagram of the main part of Figure 4, and Figure 7 is a waveform diagram of the main part of Figure 1. FIG. 8 is a groove bottom diagram of the time axis fluctuation component correction device and special playback control device according to the invention, and FIG. 8 is a waveform diagram of the main part of FIG. 7. FIG. 9 is a block diagram of the time axis fluctuation component correction device and special playback control device of the second invention, and FIG. 10 is a waveform diagram of the main part of FIG. 9. (11)...Signal detection means, (12)...Reproduction horizontal synchronization signal separation section, (13)...Reference signal generation section, (
14)...Trapezoidal wave generation section, (15)...Sample hold section + (16)...Integrator section. (17)...Tangential direction signal detection means drive section, (18)
...control section, (19)...radial direction signal detection means drive section, (20) (21)...switching section agent Yoshihiro MorimotoFigure 3

Claims (1)

[Scope of Claims] 1. Signal detection means for detecting information signals recorded in a spiral or concentric manner on a disk-shaped recording medium, and a signal detection means for detecting information signals recorded on a disk-shaped recording medium in an adjacent track or a plurality of tracks apart. a forced transfer means for forcibly moving the signal to a track; and a control signal responsive to a time axis fluctuation component of the reproduced signal detected by the signal detection means and applied to the signal detection means to detect the time axis fluctuation component. while the signal detecting means is being forcibly moved by the forcibly moving means, the control signal corresponding to the time axis fluctuation component of the reproduced signal is set to a value that is approximately the same as the median value of the range of change. A recording disk reproducing device configured to replace the time axis fluctuation component correction control with the following. 2. A signal detecting means for detecting an information signal recorded in a spiral or concentric manner on a disc-shaped recording medium, and a signal detecting means for detecting an information signal recorded on an adjacent track or a track of the information signal separated by a plurality of tracks. a correction means for generating a control signal according to a time axis fluctuation component of the reproduced signal detected by the signal detection means and applying it to the signal detection means to reduce the time axis fluctuation component; and while the signal detecting means is being forcibly moved by the forcible transfer means, the control signal corresponding to the time axis fluctuation component of the reproduced signal is approximately the same as the value immediately before the signal detecting means is forcibly moved. A recording disk reproducing device configured to hold the value at .