Patent ID: 7277367
Filing Date: 2007-10-02
Classification: G11B

Abstract:
1. A tracking error detection device for an optical disk apparatus using a modulation coding method in which a minimum value of a run-length is 1, the device comprising: a detecting unit which includes at least two detectors and detects a reflected light from a series of pits formed on an optical disk; a phase comparing unit which detects a phase difference of outputs of the at least two detectors; and a low-pass filter which smoothes an output of the phase comparing unit, a cut-off frequency of the low-pass filter being higher than a frequency at which a spectrum of a modulation code recorded in the optical disk becomes −10 dB relative to a frequency component of a code before modulation and lower than a frequency at which the spectrum of the modulation code recorded in the optical disk becomes −5 dB.