US Patent 7486595 Tracking error detector

A tracking error detector receives laser light that is irradiated onto tracks on a disc surface and that is reflected from the tracks by using a light-receiving device having divided portions, binarizes signals output from the light-receiving device having divided portions in accordance with the amount of tracking error by using a signal processing circuit including a binarization circuit, and outputs a tracking error signal for tracking control on the basis of a phase difference between the binarized signals. The tracking error detector includes an inter-signal amplitude difference adjustment circuit for determining an amplitude difference between signals output from the light-receiving device, for adjusting the amplitude difference between the signals, the amplitude difference being binarized by the signal processing circuit, for equalizing the phase offset of each of the signals, and for suppressing the phase offset with respect to the tracking error signal.