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. 27, 2001
Filed:
Dec. 23, 1998
Satoshi Imai, Tokyo, JP;
Yoshito Asoma, Saitama, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical pickup and an optical disk unit based on the optical pickup, which are capable of reducing their sizes, and of providing a low-cost construction, and further, of allowing accurate servo. The optical pickup comprises an optical separating section which is, in its optical source side surface, equipped with a first diffraction grating and an optical path branching section composed of a plurality of surfaces having normal vectors different from each other, and which is, in its optical disk side surface, equipped with a second diffraction grating composed of a continuous area. The first diffraction grating divides light from a light source into main and side beams, while the second diffraction grating allows the light from the light source to pass and diffracts the returning light from an optical disk toward the optical path branching section. The optical path branching section divides the returning light from the optical disk to lead the divisions to light-receiving sections of an optical detector.