US 5,398,224 AGranted

Optical disk reproducing apparatus having a track jump control means

AssigneePioneer Electronic Corporation

InventorHiroyuki Takahashi

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Abstract

An optical disk reproducing apparatus having a brake device for emitting a brake signal includes a track jump control device adapted to inhibit, during a track jump operation, the operation of the brake device until a predetermined period has elapsed starting from a time not earlier than the termination of the emission of the brake signal. Thus, the brake device does not operate until the emission of the brake signal has been terminated, so that, if there is some defect in the target track to which the pickup is to be jumped, the brake device does not malfunction. Accordingly, the drive device can reliably effect a track jump even if the target track of the track jump has some defect. Further, the brake device operates after the above-mentioned predetermined period has elapsed, so that, if a track stray happens to occur due to some defect in the target track, the effect of such a defect can be reduced.

Claims5

Dependent claims

An optical disk reproducing apparatus comprising:

a pickup for applying a light beam to a track formed on an optical disk being rotated so as to form a light spot thereon and to obtain a read signal based on a light beam reflected by the optical disk;
a drive means for driving said pickup in a radial direction of the optical disk;
a tracking error detecting means for producing a tracking error signal on the basis of the read signal;
a tracking servo means, provided in a tracking servo loop, for performing a tracking servo operation on the basis of the tracking error signal;
a track jump control means for supplying a track jump signal to said drive means so as to transfer the pickup to a desired position, the track jump signal including a jump pulse signal of a first polarity and a brake pulse signal, following the jump pulse signal, of a second polarity opposite to the first polarity;
a brake means for repeatedly opening and closing the tracking servo loop during a track jump operation in accordance with the read signal and the tracking error signal;
and
a brake control means for counting a time period starting from a time when the brake pulse signal returns to zero and for activating the brake means when the time period counted becomes equal to a predetermined, constant time period.

5 more elements

Dependencies are inferred from the claim text.