Optical disk drive for compensating wobble signal and method thereof

An optical disc drive used for accessing an optical disc, wherein the optical disc drive comprises:

• a servo controller;
• and
• an optical pick-up head electrically coupled with the servo controller, wherein the optical pick-up head comprises:
• a laser diode for emitting a beam;
• an objective lens for focusing the beam on the optical disc;
• and
• a photo detector for receiving a reflective beam generated by the optical disc drive according to the beam and outputting a plurality of photo detecting signals accordingly;
• wherein, after receiving the photo detecting signals, the servo controller generates a processed signal accordingly, moves the objective lens according to the processed signal when the absolute value of the processed signal is larger than a fixed value, and enables the photo detector to receive the reflective beam to generate the photo detecting signals until the absolute value of the processed signal is not larger than the fixed value;
• wherein when the absolute value of the processed signal is not larger than the fixed value, the photo detector receives the reflective beam and outputs a plurality of calibrated electrical signals accordingly, and the servo controller generates a wobble signal according to the calibrated electrical signals.