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:
Nov. 05, 1996
Filed:
Dec. 07, 1994
Koichi Yamazaki, Sakado, JP;
Kazuo Noda, Yokohama, JP;
Yonezo Furuya, Hatoyama, JP;
Yasuyuki Kimura, Kawagoe, JP;
Nippon Conlux Co., Ltd., Tokyo, JP;
Abstract
In a tracking or focusing servo control loop, there are provided a switch element for switch-controlling a tracking or focusing error signal, and a smoothing circuit for switching passage the error signal. An amount of detected reflection from an optical recording medium is monitored by a controller section, and the switching action of the switch element is ON/OFF-controlled by the controller section so as to maintain a servo loop gain at a predetermined standard. Thus, it is possible to maintain a constant servo loop gain without being influenced by variation in the laser light amount or difference in reflectivity characteristics of the recording layers of individual optical recording media, and constantly stable tracking servo control and/or focusing servo control can be performed.