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. 05, 1995
Filed:
Apr. 07, 1994
Naoya Eguchi, Tokyo, JP;
Atsushi Fukumoto, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical pickup apparatus for irradiating a light beam on an optical recording medium for recording or reproduction, including a light source, an objective lens, a nonpolarization beam splitter, a photodetector, and a 1/4 wavelength plate. The objective lens focuses the light beam radiated from the light source on to the recording layer of the optical recording medium. The nonpolarization beam splitter is disposed between the objective lens and the light source and separates the light beam emitted from the light source and the light beam reflected by the recording layer of the optical recording medium. The photodetector receives the beam of light reflected by the recording layer of the optical recording medium which has been separated by the nonpolarization beam splitter and deflected 90.degree. in optical path. The 1/4 wavelength plate is disposed on the path of emission of the light beam emitted from the light source between the nonpolarization beam splitter and the optical recording medium.