Patent ID: 6459663
Filing Date: 2002-10-01
Classification: G11B

Abstract:
An apparatus for correcting an offset included in a tracking-error signal indicative of a difference between a position of an information track formed on a storage medium with information to be reproduced and a position of an optical beam irradiated onto the storage medium to reproduce the information, the apparatus comprising:producing means for producing the tracking-error signal in an analog form based on a reflected beam of the optical beam from the storage medium; first adding means for adding a first offset-correcting signal to the analog tracking-error signal for removal of the offset therefrom, thereby producing an added tracking-error signal in the analog form; digitizing means for digitizing the added tracking-error signal to produce a digital tracking-error signal; second adding means for adding a second offset-correcting signal to the digital tracking-error signal for removal of the offset therefrom, thereby producing an added digital tracking-error signal; detecting means for detecting the offset corresponding to a difference between a center level of the tracking-error signal and a preset reference level; comparing means for comparing the detected offset with a threshold preset based on a maximum amplitude of the tracking-error signal; and controlling means for providing the first offset-correcting signal for the first adding means when the comparing means show that the detected offset is not less than the threshold, and for providing the second offset-correcting signal for the second adding means when the comparing means show that the detected offset is smaller than the threshold.