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:
Jan. 10, 2006
Filed:
May. 16, 2000
Alex Bradshaw, Kawagoe, JP;
Yuichi Kimikawa, Kawagoe, JP;
Shinichi Naohara, Kawagoe, JP;
Norio Matsuda, Kawagoe, JP;
Alex Bradshaw, Kawagoe, JP;
Yuichi Kimikawa, Kawagoe, JP;
Shinichi Naohara, Kawagoe, JP;
Norio Matsuda, Kawagoe, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
Two sum output signals from two sets of the photodetector elements located symmetrically each other with respect to a light-receiving center of the photodetector of the optical pickup are amplified individually by two amplifiers. A focus error signal is generated in accordance with a difference between respective output levels of the two amplified signals. The gains of the two amplifiers are adjusted in accordance with the focus error signal. A predetermined bias voltage is applied to the focus error signal line in the focus servo control means in accordance with the focus error signal.