JPH0536219A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To share the use of a time base collector used at the time of recording and reproducing, to prevent going over a jitter correction range due to jitter existing in a video signal which has to be recorded already and to realize a low cost and stable recording and reproducing device. CONSTITUTION:The output from a switch 12 selecting and switching a reproduced signal reproduced by an optical disk j, an optical head 2, a signal generator 6 and a demodurator 7 to a video signal input 10 is added to the time base collector then a video signal without jitter is obtained at an output 11. At the time of recording, the signal from this output 11 is recorded in the optical disk 1 by a modulator 4, a signal recorder 5 and the optical head 2. And at the time of reproducing, a synchronous signal from a synchronous signal generator 18 is phase-adjusted by a phase adjustor 18 and added to a phase comparing motor controller 9 with a synchronous signal obtained from the signal generator 6 at the time of reproducing, then phase-controls a motor 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus, and more particularly to an apparatus for recording / reproducing a video signal on a recordable disk.

[0002]

2. Description of the Related Art A recordable optical disk has a groove (groove), and when an information signal is recorded, it is recorded on the groove. Generally, an optical disc has an eccentricity, and a video signal recorded on the optical disc has a jitter due to the eccentricity, and it is necessary to correct the jitter during reproduction. However, there is a limit to the jitter correction at the time of reproduction. For example, when the video signal to be recorded already has jitter, when recording / reproducing, jitter more than the jitter due to the eccentricity of the optical disc occurs at the time of reproduction, so that the jitter correction range However, normal recording and reproduction could not be performed. For this reason, conventionally, a video signal to be recorded on an optical disk is recorded on the optical disk after being passed through a time base collector so that there is no jitter.
At the time of reproduction, a reproduction video signal was reproduced using a jitter correction device incorporated in the recording / reproduction device.

[0003]

By the way, since the video signal input to the recording / reproducing apparatus is supplied from various devices, the time base collector for correcting the jitter of the input video signal has a complicated structure and cost. It was also expensive.
Further, since the recording / reproducing apparatus has a built-in jitter correcting apparatus used at the time of reproducing, the total cost is further increased. An object of the recording / reproducing apparatus of the present invention is to solve the above-mentioned conventional problems, to correct jitter with a simple configuration to improve performance, and to obtain a low-cost recording / reproducing apparatus.

[0004]

In order to achieve the above object, the recording / reproducing apparatus of the present invention comprises a reproducing means from a recording medium, one of which is connected to a video signal input and the other is connected to an output of the reproducing means. The switching means, the time base collector having an input terminal connected to the switching means, and the recording means connected to the output of the time base collector for recording on the recording medium. Is configured to obtain a video signal output from the output of.

More specifically, the read clock of the time base collector is synchronized with the output of the synchronizing signal generator, and the output of the phase adjuster connected to the output of the synchronizing signal generator and the synchronizing signal from the reproducing means are connected. In addition to the phase comparison motor controller, the motor that controls the rotation of the optical disk that is the recording medium is phase-controlled, and the synchronization signal of the video signal output via the time base collector during reproduction and the time base during recording are controlled. It is also possible to adopt a configuration in which the phase difference between the output signal of the collector and the synchronizing signal is set to a specified value or less.

Further, if necessary, a write clock generator for controlling the optical disc eccentricity information obtained from the optical head is provided.

[0007]

The recording / reproducing apparatus of the present invention has the above structure.
By using a single time base collector for recording and reproducing, it is possible to improve the jitter improving performance with a simple structure.

Even if a single time base collector is used, the phase of the reproduction signal is made to coincide with the recording signal so that the video output can be changed from the recording state to the reproducing state and vice versa. Disturbance of signal synchronization does not occur.

Further, since the write clock generator is controlled by the eccentricity information of the optical disc obtained from the optical head, the jitter caused by the eccentricity of the optical disc during reproduction can be efficiently corrected.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a recording / reproducing apparatus according to an embodiment of the present invention. Block A in FIG.
Is an optical disk recording / reproducing device, and block B is a time base collector. In block A, 1 is an optical disk, 2 is an optical head, 3 is a motor for rotationally driving the optical disk 1, 4 is a modulator for modulating a video signal supplied as an input 10 after passing through a time base collector B, 5
Is a signal recorder for supplying the output of the modulator 4 to the optical head 2, and modulates the output laser light of the optical head 2. Reference numeral 6 denotes a signal regenerator that amplifies the reproduction signal of the optical head 2 and detects the rotation reference signal recorded on the optical disc 1, and 7 is a demodulator that demodulates the signal recorded on the optical disc 1 into a video signal.

In the time base collector of the block B, reference numeral 12 is a switch which is a switching means.
Any one of 12b is input to the A / D converter 13, and is connected to 12a for recording and 12b for reproducing. When the switch 12 is set to the recording mode, the recording preparation signal is output prior to the recording because the recording preparation signal must be output prior to the recording start.
Set 2 to the recording mode. The recording preparation signal is block A
It is generated by a controller (not shown) for controlling the optical disk recording / reproducing apparatus of No. 1.

A memory device 14 writes the output of the A / D converter 13 with the output 16a of the write clock generator 16 and reads the written signal with the output 17a of the read clock generator 17. Reference numeral 15 is a D / A converter, 16 is a write clock generator, 17 is a read clock generator, 18 is a synchronizing signal generator, and 11 is an output of the time base collector of the block B.

In block A again, 8 is a phase adjuster and 9 is a phase comparator, which detects the phase difference between the output of the phase adjuster 8 and the output signal of the signal regenerator 6 and controls the motor 3 to control the optical disk 1. The rotation phase of is synchronized with the output of the synchronization signal generator 18.

The above-mentioned construction is described below. During recording, input video signal 1
0 is input to the time base collector B via the terminal 12a of the switch 12, and a video signal having no jitter is output to the output 11. That is, the video signal digitized by the A / D converter 13 is written in the memory device 14 by the write clock 16a having the same time axis fluctuation as the input video signal, and the time axis fluctuation of the output 17a of the read clock generator 17 is performed. Without a clock, D /
The A converter 15 converts the video signal into a video signal having no jitter component.

Video signal output 11 having no jitter component
Is FM-modulated by the modulator 4 and modulates the laser output of the optical head 2 through the signal recorder 5 to record a signal on the optical disc 1. It is assumed that the modulator 4, the signal recorder 5, and the optical head 2 constitute recording means. At this time, the optical disc 1 rotated by the motor 3 has a synchronization signal generator 18
The output signal is synchronized with the phase of the output signal of 1 and is rotated by the phase adjuster 8 while maintaining a specified phase difference from the output phase of the synchronization signal generator 18.

The phase adjuster 8 is for variably adjusting the phase of a pulse signal which is a synchronizing signal. For example, a clock pulse having a fixed cycle is applied to a shift register,
The number of stages of the shift register can be variably controlled to change the phase.

Further, when the input video signal 10 is generated in a system completely independent of the output of the synchronizing signal generator 18, the time base collector of the block B is used as a frame synchronizer to obtain a stable video signal at the output 11. It is possible.

Next, at the time of reproduction, the signal recorded on the optical disk 1 is read by the optical head 2, converted into a video signal by the signal regenerator 6 and the demodulator 7, and passed through the terminal 12b of the switch 12 to the time base. The video signal having no jitter component is obtained at the output 11 by the collector B. It is assumed that the optical head 2, the signal regenerator 6 and the demodulator 7 constitute a regenerating means.

The switch 12 is used to record and reproduce modes.
However, if the phase of the sync signal of the video signal obtained at the output 11 changes each time when switching is performed, the output 11 can be observed on a monitor TV or recorded by a VTR. When it is doing, synchronization is disturbed and it is inconvenient.

In the present invention, by adjusting the phase adjuster 8 even during recording, the switch 12 can be used during recording and reproduction.
It is possible to prevent the phase of the synchronizing signal of the video signal obtained at the output 11 from changing when switching is performed, and the synchronization is not disturbed.

The write clock generator 16 is typically a PL
It is configured by using L, but the response characteristic of this PLL is the same when the signal from the optical disc 1 is input.
It is also possible to effectively correct the jitter due to the eccentricity. That is, for example, when the rotation speed of the optical disc 1 is 30 Hz, the response characteristic of the PLL is 30 Hz.
The gain of the PLL loop can be increased so that the jitter of 1 is effectively reduced. By doing so, it becomes possible to correct the jitter of the reproduced video signal even when the signal is recorded / reproduced on the optical disc having a large eccentricity.

The beam spot emitted from the optical head is held on the track of the optical head by the tracking servo, and the objective lens of the optical head follows the eccentricity of the optical disk. Since the above-mentioned jitter is generated by the eccentricity, a signal equivalent to the jitter (eccentricity information) can be obtained by converting the magnitude of the eccentricity into an electric signal and differentiating it. A signal equivalent to this jitter is supplied to the PLL rule.
It is also possible to efficiently correct the jitter of the reproduced signal from the optical disk by adding it to the control input for controlling the oscillation frequency of the variable frequency generator (VCO) of the optical disk (that is, performing the feed forward). .

Although the present invention has been described in the example of application to the optical disk recording / reproducing apparatus, it is effective when applied to all apparatuses which may generate jitter during recording / reproducing.
For example, it can be applied to a VTR or the like.

[0024]

As described above, according to the recording / reproducing apparatus of the present invention, the single time base collector is selectively used at the time of recording and at the time of reproducing, thereby improving the jitter performance with a simple structure and at a low cost. Can be obtained.

Even if a single time base collector is used, the phase of the reproduction signal is made to coincide with the recording signal, so that the output video is switched when the recording state is changed to the reproduction state and vice versa. It is possible to prevent the disturbance of signal synchronization.

Further, since the write clock generator is controlled by the eccentricity information of the optical disc obtained from the optical head, the jitter caused by the eccentricity of the optical disc during reproduction can be efficiently corrected.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording / reproducing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1 optical disc 2 optical head 3 motor 4 modulator 5 signal recorder 6 signal regenerator 7 demodulator 8 Phase adjuster 9 Phase comparison motor controller. 10 inputs 11 outputs 12 switches 13 A / D converter 14 memory devices 15 D / A converter 16 Write clock generator 17 Read-out clock generator 18 Sync signal generator

Claims (3)

[Claims] 1. A reproducing means from a recording medium; a switching means, one of which is connected to a video signal input and the other of which is connected to an output of the reproducing means; and a time base collector having an input terminal connected to the switching means. A recording / reproducing apparatus comprising recording means for recording on the recording medium, which is connected to the output of the time base collector, and obtains a video signal output from the output of the time base collector. 2. A phase comparison motor in which the read clock of the time base collector is synchronized with the output of the synchronizing signal generator, and the output of the phase adjuster connected to the output of the synchronizing signal generator and the synchronizing signal from the reproducing means are synchronized. In addition to the controller, the motor that controls the rotation of the optical disk that is the recording medium is phase-controlled, and the synchronizing signal of the video signal that is output via the time base collector during playback and the output of the time base collector during recording 2. The recording / reproducing apparatus according to claim 1, wherein the phase difference between the signal and the synchronizing signal is set to a specified value or less. 3. The recording / reproducing apparatus according to claim 2, further comprising a write clock generator controlled by eccentricity information of the optical disk obtained from the optical head.