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:
Apr. 19, 2005
Filed:
Oct. 04, 2001
Masato Sakamoto, Kawagoe, JP;
Masato Sakamoto, Kawagoe, JP;
Pioneer Corporation, Tokyo-To, JP;
Abstract
For reproducing information recorded on an optical disc, a pickup is used to detect a target track on the disc through an optical beam. In carriage servo control, movement of the pickup is servo-controlled in the radial direction of the optical disc. In this control, a tracking error signal is produced by a preamplifier. A pulse signal is produced, in which the period of the pulse signal is set to a constant amount corresponding to the accuracy of movement of the pickup. The duty ratio of the pulse signal is changed based on characteristic of the error signal, so that a changed pulse signal is produced. The changed pulse signal is multiplied by the tracking error signal, so that a carriage control signal is produced. The carriage control signal is supplied to a carriage motor by a driver, so that the pickup is moved.