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:
May. 21, 2002
Filed:
Aug. 05, 1999
Tetsuo Ueyama, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An optical pickup device comprises a semiconductor laser, an optical system which converges light projected by the semiconductor laser onto an optical disk and directs reflected light from the optical disk to a photoreceptor element, and a photoreceptor element which detects the reflected light; the photoreceptor element including at least two main photoreceptive domains divided from one another by a dividing line, which receive reflected light corresponding to a focusing error of the light projected onto the optical disk, and at least one auxiliary photoreceptive domain which detects reflected light which exceeds the main photoreceptive domains in a defocused state; in which the auxiliary photoreceptive domain is provided adjacent to an end of said main photoreceptive domains in the direction of the dividing line.