JP2581178Y2 - Rotation control device for optical disk device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary servo device for an optical disk recording / reproducing apparatus, and more particularly to a means for improving a rotary servo performance when reproducing a partially recorded disk.

[0002]

2. Description of the Related Art A recordable optical disk such as a CD-R or MD is provided with a pregroove having a waveform for guiding a light spot. At the time of reproducing the optical disk, a wobble signal that fluctuates according to the wave of the pregroove is obtained.

When reproducing a partially recorded disk, a wobble signal is input to a rotary servo circuit, which controls the rotation of the disk motor so that the center frequency of the wobble signal is constant.

FIG. 2 shows an example of such a conventional rotary servo device. The optical disk 2 clamped on the rotation axis of the disk motor 1 is rotated by the disk motor 1, and a laser beam is irradiated by the optical pickup 3 onto the pre-groove of the optical disk 2 and the pit train of the signal recorded thereon, and its reflection is performed. Light is received by the light receiving element of the optical pickup 3.

[0005] The output current of the light receiving element is determined by the RF signal processing circuit 4.
And from the RF signal processing circuit 4 to the rotary servo circuit 5
Outputs a wobble signal. The rotation servo circuit 5 controls the rotation of the disk motor 1 so that the center frequency of the wobble signal becomes constant.

[0006]

[Problems to be Solved by the Invention] When reproducing an optical disk on which partial recording has been performed, time information included in the wobble signal may be reproduced from an unrecorded part. As shown in the above-mentioned conventional optical disk reproducing apparatus, the wobble signal obtained from
It was used as an input signal for a rotary servo circuit.

However, in an optical disk on which recording has been completed, a clock extracted from a recording signal is used as an input to a rotary servo circuit as in a CD player, in which case jitter during recording is eliminated. On the other hand, in the conventional optical disk reproducing apparatus, there is a disadvantage that the jitter at the time of recording appears in the reproduced signal of the partial recording section because the wobble signal is used as the reference signal of the rotary servo.

The present invention has been made in view of the above points, and a purpose thereof is to provide a rotary servo device of an optical disk recording / reproducing apparatus in which jitter during recording is eliminated when reproducing a partially recorded optical disk. Is to provide.

[0009]

SUMMARY OF THE INVENTION A rotation control device for an optical disk device according to the present invention is an optical disk device capable of recording or reproducing information on a recordable optical disk. The rotation control of the disk is performed based on the clock signal extracted from the recording signal in the portion where the signal is recorded, and is performed based on the wobble signal previously recorded on the disk in the portion where the signal is not recorded. As described above, the switching is performed according to the recording presence / absence detection signal.

[0010]

The presence or absence of recording can be easily detected by comparing the amplitude of a signal reproduced from the optical disk with a predetermined value.
According to the rotary servo device of the optical disk recording / reproducing apparatus of the present invention, the clock extracted from the recording signal is input to the rotary servo circuit in the portion where the signal is recorded by the recording presence / absence detection signal detected as described above. As described above, the input signal of the rotary servo circuit is switched, so that the jitter generated at the time of recording is erased and the rotation unevenness is eliminated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotary servo device of an optical disk recording / reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG.
FIG. 1 is a block diagram showing a rotary servo device according to an embodiment of the present invention. The optical disk 2 clamped on the rotation axis of the disk motor 1 is rotated by the disk motor 1, and a laser beam is irradiated by the optical pickup 3 onto the pre-groove of the optical disk 2 and the pit train of the signal recorded thereon, and its reflection is performed. Light is received by the light receiving element of the optical pickup 3.

The RF signal reproduced by the light receiving element is input to an RF signal processing circuit 4 and a recording presence / absence detecting circuit 7. The wobble signal is output from the RF signal processing circuit 4 to the terminal of the changeover switch 8, and the EFM signal is output to the decoder 6. The decoder 6 extracts the basic clock from the EFM signal and outputs it to the terminal of the changeover switch 8.

The recording presence / absence detection circuit 7 extracts the peak envelope of the RF signal, compares the peak envelope with a predetermined voltage, and outputs an H or L signal. In this manner, when reproducing the portion of the disk where the signal is recorded, the clock extracted from the recording signal is input to the rotary servo circuit 5, and in the portion where no signal is recorded, the wobble signal is supplied to the rotary servo circuit 5. Is input to

The rotation servo circuit 5 controls the rotation of the disk motor 1 so that the center frequency of the wobble signal has a predetermined frequency or the clock extracted from the recording signal has a constant frequency.

[0015]

According to the rotary servo device of the optical disk recording / reproducing apparatus of the present invention, when reproducing the partially recorded optical disk, the jitter at the time of recording is eliminated, so that the reproducing characteristics such as an error rate are improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a rotary servo device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a flow of a rotary servo signal at the time of reproducing a partially recorded optical disk in a rotary servo device of a conventional optical disk recording / reproducing apparatus.

[Explanation of symbols]

 Reference Signs List 1 disk motor 2 optical disk 3 optical pickup 4 RF signal processing circuit 5 rotation servo circuit 6 decoder 7 recording presence / absence detection circuit 8 changeover switch

Claims (1)

(57) [Scope of request for utility model registration] 1. An optical disc apparatus capable of recording or reproducing a recordable optical disc, comprising: a recording presence / absence detection circuit for outputting a recording presence / absence detection signal in response to an RF signal input; In the optical disc apparatus, the switching is performed based on a clock signal extracted from a recording signal, and switching is performed by the recording presence / absence detection signal so that a portion where no signal is recorded is performed based on a wobble signal previously recorded on the disk. Rotation control device.