Patent ID: 7009921

Claim:
A method of detecting a playback signal using a photodetector which multi-divides an optical signal reflected from an optical recording medium for detection, the method comprising: detecting a first signal corresponding to information along a first tangential line of the optical recording medium; detecting a second signal corresponding to information along a second tangential line of the optical recording medium; binarizing the first and second signals to provide first and second binarized signals; inputting a control signal which designates a data length to be compensated; detecting a phase difference between portions of the first and second binarized signals having the designated data length to provide a time delay compensation signal; temporally shifting the portions of the second signal having the designated data length based on the time delay compensation signal to temporally match the portions of the first and second signals having the designated data length while passing data having lengths other than the designated data length without temporally shifting the data having the other lengths; and summing the first signal and the second signal having the temporally shifted portions to output the playback signal.