Light modulation method for optical disk drive device
AssigneeFujitsu Limited
InventorsToru Ikeda, Shigenori Yanagi, Akira Minami
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Abstract
A recovery is promptly executed for a reading error of a track address in a modified constant angular velocity format. Upon seeking, when a defective reading operation of the track address occurs, a clock frequency of the zone corresponding to each detecting position is selected due to the detection of the head by a head position sensor or the movement of the head to a home position at which a detection signal of a home position sensor is obtained, and the reading operation is retried. Errors due to back talk noises upon reproduction are reduced. At the time of retry for the occurrence of errors due to the back talk noises, a modulation amount of a read beam from a laser diode is changed.
Claims8
An optical disk apparatus comprising:
- laser light emitting means for emitting a reproduction laser beam;
- light emission control means for controlling a light emission amount of said laser light emitting means;
- modulating means for high frequency modulating a reproduction light of said laser light emitting means;
- and
- control means for changing a modulation amount of said modulating means in the case where an error exceeding an error correcting ability occurs upon reproduction of data, and allowing a retry operation of the data reproduction to be executed.
Dependencies are inferred from the claim text.