Patent ID: 7092322
Filing Date: 2006-08-15
Classification: G11B

Abstract:
1. A method of calibrating a focus error signal offset in a focus servo system having a servo processor for an optical disk drive, the method comprising: closing the focus servo system with the focus error signal offset set to a first value while a tracking servo system is off, the servo processor calculating a focus error signal from optical signals received from detectors in an optical pick-up units; (a) decrementing the focus error signal offset from a starting value until a maximum in a peak-to-peak value of a tracking error signal is located; assigning a value of the focus error signal offset corresponding to the maximum of the peak-to-peak value of the tracking error signal determined in act (a) to a current best offset value; (b) incrementing the focus error signal offset from the starting value until a maximum in the peak-to-peak value of the tracking error signal is located; if the peak-to-peak value of the tracking error signal determined in act (b) is greater than the peak-to-peak value determined in act (a), assigning the current best offset value to a value of the focus error signal offset corresponding to the maximum of the peak-to-peak value of the tracking error signal determined in act (b).