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. 17, 1996
Filed:
May. 31, 1994
Shuichi Ichiura, Hashima, JP;
Osamu Ota, Ibi-gun, JP;
Sanyo Electric Co., Inc., , JP;
Abstract
An optical pickup device provides an ultraresolving prism between a semiconductor laser and an objective lens so as to reduce light intensity at around a cross sectional center of a laser beam, thereby generating ultraresolution thereon. An optical detector is disposed at a signal detecting position where the laser beam reflected by an optical disk is converged. The optical detector has a detecting element for receiving a main lobe and a pair of detecting elements for receiving a pair of side lobes. A peak of a shielding portion of the prism is inclined to a track center of the optical disk so that the side lobes are oppositely shifted from the track center. Thus, tracking error signals are obtained on the basis of detected signals in the side lobes.