Matsushita Electric Industrial Co., Ltd.

Kunimasa Kusumoto

Mitsuteru Fujimoto

At spin-up of an optical diskgain adjustment and offset adjustment are performed on a servo error signal to obtain a first gain adjustment value and a first offset adjustment value. Based on the first gain adjustment value, a CPUobtains a second gain adjustment value and a second offset adjustment value at data writing on the optical diskand stores them in storageWhen the reading state of the optical diskshifts to the writing operation, the CPUcontrols a laser power switching circuitto change the output from an optical pickupand, simultaneously, reads the second offset adjustment value and gain adjustment value stored in the storageand sets them in an offset adjustment unitand a gain adjustment unitrespectively.

Optical disk drive having gain control to maintain stability of a servo system

The present invention relates to loop gain adjustment of a focus/tracking servo in an optical disk apparatus, and provides an optical disk apparatus which can make the loop gain adjustment converge normally even in an optical disk in which prerecorded areas and recorded areas are mixed, and further which always has a stable servo system even when a gain is significantly varied due to changes in the disk state. When an inserted optical disk is determined to be a recordable optical disk by an optical disk type determination means, an optical pickupis made seek a previously set area, thereby performing the loop gain adjustment. Further, when a gain is varied during the operation, a gain adjusting meanschanges over a gain adjustment value.

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Saijo, Japan

Kunimasa Kusumoto