Mitsubishi Electric Corporation

Teac Corporation

Takuya Nagata

Kyosuke Yoshimoto

Hiroyuki Onda

Kazuhiko Nakane

Akira Mashimo

Yoshihiro Kiyose

Hidehiko Murata

Koji Yamana

Teruo Furukawa

Minoru Ozaki

Osamu Ito

Yutaka Kobayashi

A miniaturized optical disk apparatus which performs a pull-in of a focus servo and a pull-in of a tracking servo without a position detector for detecting an optical head. If the optical head is located at a non-reflection film area and thus the focus servo cannot be performed, then the optical head is moved and the focus servo is performed again. This process is repeated until the focus servo can be achieved. In addition, if the optical head is located at a non-track area, then the optical disk is moved to a track area and then the tracking servo is performed. This process also repeated until the optical head is located over the track area. The tracking servo can be stably performed since it is performed only when the optical head is located over the track area. The present invention is applicable to the optical disk apparatus which uses a 3.5 in optical disk.

Optical disk storage which provides pull-in of focus servo and pull-in

A method for rewriting four defect management areas on an optical disk according to an ECMA standard is performed by means of deleting an old data which has been recorded on the respective defect management areas and then sequentially writing down a new data on respective defect management areas.

Method for rewriting defect management areas on optical disk according

An optical or magneto-optical disk storage which automatically adjusts a recording/reproducing level of a number of kinds of optical or magneto-optical disks having different recording/reproducing levels to an optimum recording/reproducing level. The optical or magneto-optical disk storage has an attenuator which applies a predetermined attenuation amount to a reproduced signal reproduced from an optical or magneto-optical disk so as to attenuate the reproduced signal, or intensity adjusting means for adjusting the intensity of a laser beam used for recording and/or reproducing. The optical or magneto-optical disk storage detects an amplitude of the reproduced signal and feed-back-controls the attenuation amount or intensity of the laser beam in accordance with the detected amplitude.

Disk storage which automatically adjusts to optimum

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Hoya, Japan

Takuya Nagata