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. 23, 2007
Filed:
Apr. 28, 2004
Yasutaka Suzuki, Kawagoe, JP;
Kazunori Matsuo, Kawagoe, JP;
Yasutaka Suzuki, Kawagoe, JP;
Kazunori Matsuo, Kawagoe, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
A temperature sensor () detects a temperature of a spindle motor () of a rotary drive unit () for rotating a disk-shaped recording medium (), and a temperature information acquiring unit (A) acquires the temperatures as temperature information. An eccentricity detector () detects a drive voltage level, and an eccentricity information acquiring unit (B) acquires the drive voltage level as eccentricity information. When a determining unit (C) determines that the temperature is higher than a predetermined temperature or that the drive voltage level is higher than a predetermined voltage, a servo controller () switches a rotation mode from constant liner velocity to constant angular velocity. That enables stable information processing over a long time with a simple strucure for constant linear velocity.