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:
Sep. 03, 2002
Filed:
May. 27, 1998
Applicant:
Inventors:
Assignee:
Pioneer Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/00 ;
U.S. Cl.
CPC ...
G11B 7/00 ;
Abstract
An optical pickup device includes a photodetector divided into four light-receiving elements by two dividing lines, an incident optical system for irradiating a light beam onto an optical recording medium, and a receiving optical system for guiding a return light from the optical recording medium to the photodetector, wherein the receiving optical system includes astigmatism generating means for generating astigmatism having an astigmatism axis at an angle of 45 degree with respect to the two dividing lines.