The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 1999
Filed:
Jan. 17, 1997
Harushige Nakagaki, Yokohama, JP;
Tokinori Furuichi, Yokohama, JP;
Kazuhiro Oda, Chigasaki, JP;
Ryuichi Koike, Chigasaki, JP;
Hideo Suenaga, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An method to prevent excessive heat generation of the pickup actuator from occurring when a disk has a large eccentricity or planar vibration in a high-speed disk reproducing apparatus using an optical pickup. The disk reproducing apparatus has a status determining arrangement for monitoring a present actuator drive state, an analyzing arrangement for analyzing an output signal of the status determining arrangement, and disk rotational speed switching control arrangement for selecting disk reproducing speeds according to a control signal of the identification means, thereby lowering the reproducing speed when the eccentricity or planar vibration is large. Such invention prevents heat generation of the pickup actuator from occurring because high-speed reproduction can be performed when the eccentricity or planar vibration is small, and reproduction speed can be automatically reduced when the eccentricity or planar vibration is large.