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:
Dec. 25, 2001
Filed:
Jul. 21, 2000
Akira Miura, Saitama-ken, JP;
Taichi Akiba, Saitama-ken, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
An optical pickup device is provided with a focus error signal generating means which is adapted to calculate a first output sum signal obtained by adding together an output signal fed front one portion of the second light receiving means and an output signal fed from one portion of the third light receiving means, and to calculate a second output sum signal obtained by adding together an output signal fed from the other portion of the second light receiving leans and an output signal fed from the other portion of the third light receiving means, so as to calculate a difference between the first output sum signal and the second output sum signal, thereby producing a focus error signal.