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:
Feb. 10, 1998
Filed:
Jan. 15, 1997
Hideyoshi Horimai, Kanagawa, JP;
Tsunehiro Maruo, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical pickup device suitable for use as an optical system of; e.g., an optical disc reproducing apparatus, for carrying out reproduction of desired information on an optical disc; e.g., a magneto-optical disc, a compact disc (CD) or a video disc. The device uses diffraction and various optical rotation devices to direct the incident and reflected light rays to the optical disk and to photodetectors. More specifically, light emitted by a laser source is trisected into 0-th and .+-.1-th order light. The rays are then rotated by an optical rotation device. The rays are converged on the optical disk, reflected, and then rotated again. The rays are then deflected to a photodetector, which then produces light quantity detection signals; e.g., tracking error signal.