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:
Aug. 13, 2002
Filed:
Dec. 20, 1999
Shohei Kobayashi, Hachioji, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An optical pickup device comprises a light source, a beam converting optical system for converting a light beam emitted from the light source to a light beam having substantially circular distribution of quantity of light, an objective optical section for converging the light beam on an optical recording medium, and a signal detecting system for reproducing information recorded on the optical recording medium. The signal detecting system includes a separating optical element for separating a return light beam from a go light beam, and an signal detecting section for detecting an information signal based on the separated return light beam. The beam converting optical system has a first beam converting prism and a second beam converting prism, each of which has two optical surfaces nonparallel to each other. One of them is an entrance surface through which a light beam to be converted enters and the other is an exit surface through which the converted light beam exits. Each of the first and second beam converting prisms is arranged so that the entrance surface is oblique with respect to the optical axis and the exit surface is perpendicular to the optical axis.