Patent ID: 8134895

Claim:
A circuit for generating a tracking error signal, the circuit outputs the tracking error signal according to a first pick-up signal and a second pick-up signal outputted from a pick-up head, wherein the first pick-up signal and the second pick-up signal respectively represent reflected intensities of a main beam measured by a first light detecting element and a second light detecting element of the pick-up head, the circuit comprising: a digitizing circuit, coupled to the pick-up head, for comparing the first pick-up signal and the second pick-up signal, so as to obtain a first digital signal and a second digital signal; a short signal removing circuit, for removing pulses in the first digital signal and the second digital signal to generate a first determining signal and a second determining signal respectively when the pulse width of pulses are shorter than a preset time, wherein the short signal removing circuit is implemented using a pure digital logic circuit; and a phase comparator, for receiving the first determining signal and the second determining signal, and outputting the tracking error signal according to a phase difference between the first determining signal and the second determining signal.