Patent ID: 6167010
Filing Date: 2000-12-26
Classification: G11B

Abstract:
An apparatus for reproducing data from a disk, comprising:a pickup having a photoelectric conversion element for optically reading data recorded on a disk and converting the data to an electric signal, and an actuator to be driven;a circuit for receiving the electric signal from said photoelectric conversion element and generating a tracking error signal;an analog-to-digital converter for receiving the tracking error signal from said circuit and converting the tracking error signal into digital data;a tracking digital equalizer for selecting one of a first mode and a second mode and performing phase compensation and gain compensation which are required for a tracking servo circuit, said first mode being one for obtaining output data from the digital data supplied from said analog-to-digital converter, with a first gain, and said second mode being one for obtaining output data from the digital data supplied from said analog-to-digital converter, with a second gain smaller than the first gain;a digital-to-analog converter for converting digital data supplied from the tracking digital equalizer into an analog signal;a driver for receiving output data from the digital-to-analog converter and outputting a signal for driving the actuator of said pickup, thereby to form a feedback loop between input and output of said pickup; anda gain switching circuit connected to said tracking digital equalizer and said driver, for switching a gain in accordance with the mode selected by the tracking digital equalizer.