Patent ID: 7283432
Filing Date: 2007-10-16
Classification: G11B

Abstract:
1. A method for correcting optical path deviation of an optical pickup in an optical recording system, the optical pickup including a laser diode for emitting a laser beam, an objective lens for receiving and projecting the laser beam onto an optical recording medium, and a photo detector for detecting the light beam reflected by the optical recording medium, the optical recording system including a servo mechanism for focusing and track-locking control of the optical pickup, and a servo controller for controlling operation of the servo mechanism, said method comprising the steps of: a) generating a push-pull signal from output of the photo detector while the optical pickup is operated in a focusing and non-track-locking state; b) generating a DC level error signal by subjecting the push-pull signal to low-pass filtering; and c) generating a calibrating servo signal based on the DC level error signal and a servo control signal from the servo controller, the calibrating servo signal being applied to the servo mechanism for adjusting position of the objective lens so as to maintain the DC level of the push-pull signal at an ideal level, wherein, in step c), the calibrating servo signal is generated by applying the DC level error signal as a negative feedback to the servo control signal.