TRACKING ERROR SIGNAL GENERATION DEVICE AND TRACKING ERROR SIGNAL GENERATION METHOD

摘要

A detection signal S1 outputted from a light reception unit (11A) of detection means (11) formed by four-division light reception element is added to a detection signal S4 outputted from a light reception unit (11D) so as to obtain an addition signal S14 and a phase difference signal P1 indicating the phase difference between the addition signal S14 and the detection signal S1. Furthermore, a phase difference signal P4 indicating the phase difference between the addition signal S14 and the detection signal S4 is obtained. The phase difference signal P4 is subtracted from the phase difference signal P1 so as to generate a tracking error signal TE1.