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:
Mar. 13, 2001
Filed:
Feb. 24, 1998
Yoshio Yoshida, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
In an optical pickup, a beam splitter is arranged on an optical path between a hologram and a grating. Beam splitter includes a first reflecting surface reflecting part of a beam reflected from a disk, and a second reflecting surface arranged parallel to the first reflecting surface. Part of the beam which is reflected from the disk and passed through hologram is reflected at the first reflecting surface and thereafter reflected by the second reflecting surface of beam splitter, and thereafter directed to optical waveguide device, whereby a signal recorded on the disk is detected (reproduced). The beam which has transmitted through hologram and the first reflecting surface is directed to photodiode and detected as a servo error signal.