Matsushita Electric Industrial Co., Ltd.

Hiroyuki Gondo

Makoto Taromaru

Shingo Sagata

Kiyoyuki Suenaga

Koji Muraoka

An optical disk apparatus equipped with an objective lens for converging light from a light source onto a track formed on an optical disk, the objective lens being arranged to be movable and an error detecting section for detecting a difference in position between the light converged by the objective lens and the track on the optical disk. Included in the servo section of the optical disk apparatus are an amplifier for amplifying an output of the error detecting section with an amplification factor which is variable and a filter circuit for cutting off a frequency component of an output of the amplifying means, the cutoff frequency being variable. On the basis of the output of the filter circuit, a moving device moves the objective lens so that the difference between the converged light and said track is reduced. The amplification factor of the amplifier and the cutoff frequency of the filter circuit are determined in correspondence with the position of the objective lens. These amplification factor and cutoff frequency are prestored in a memory so that the corresponding amplification factor and cutoff frequency are read out therefrom in accordance with the current position of the objective lens.

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Chikushino, Japan

Hiroyuki Gondo