Track cross signal generation circuit of optical disk device for correctly outputting track cross signal and correctly and stably carrying out seek operation even within high speed region of beam

摘要

A track cross signal generation circuit comprises a tracking error signal generation circuit (14), an offset compensation circuit (16), a level setting circuit (22), and a comparator (24). The comparator (24) directly receives a tracking error signal (TES) output from the tracking error signal generation circuit (14) without passing through the offset compensation circuit (16) and a reference level (Vref) output from the level setting circuit (22). Further, the comparator (24) compares the tracking error signal (TES) with the reference level (Vref), and generates a track cross signal (TZC) representing the tracks formed on an optical recording medium (12) crossed by a beam. Namely, the gain of the tracking error signal (TES) is not affected by the offset compensation circuit (16) even within a high-speed region of the beam. Consequently, the track zero cross signal (TZC) correctly indicates tracks crossed by the beam, and correctly and stably carries out a seek operation in the high-speed region of the beam.