Patent ID: 7583568
Filing Date: 2009-09-01
Classification: G11B

Abstract:
1. A focus control device comprising: an optical pickup that converts reflected light of laser light irradiated onto an optical recording medium to an electrical signal; an optical member that is provided on said optical pickup and emits laser light and receives reflected light; an actuator that drives said optical member; a detection unit that detects a drive signal of said actuator using the electrical signal from said optical pickup; and an actuator drive unit that controls drive of said actuator such that said optical member performs a focus pull in action using said drive signal; a focus gain setting unit that sets the focus gain of said drive signal; and a focus gain adjustment unit that adjusts a waveform of said drive signal in a focus gain setting by said focus gain setting unit, wherein the adjustment performed by said focus gain adjustment unit is performed by magnifying the waveform of said drive signal and clipping any portion that exceeds a predetermined dynamic range and making the waveform smaller before the focusing servo action is performed.