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:
Aug. 18, 1992
Filed:
Mar. 17, 1989
Naobumi Nagasawa, Gunma, JP;
Hiroyuki Arai, Gunma, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A track search circuit includes a command decoder which decodes command data sent by a microcomputer and stored in a command register and outputs signals commanding a track jump and commanding count of a counter which counts a tracking error signal. Time difference between a present A-time and a target A-time is calculated such that an optical pick-up can be moved toward a target position by utilizing the track jump of 4.sup.n. When a counted value of the counter reaches a predetermined value, the A-time is renewed such that the time difference can be reduced by addition or subtraction suitable time data to or from the A-time. If the renewed A-time becomes within 1 minute with respect to the target A-time in repeating such a track jump in accordance with the renewed A-time, the optical pick-up is stopped to move, and the A-time is read to jump the optical pick-up again to catch the target position.