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:
Nov. 10, 1998
Filed:
Mar. 13, 1997
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369112 ; 369 4423 ;
Abstract
An optical pickup apparatus has an optical system and an objective lens. The optical system has a semiconductor laser and an optical element. The semiconductor laser has an astigmatic difference in which an oscillated light beam has a light emission point in a semiconductor junction plane different from that in a plane normal to the semiconductor junction plane. The optical element is arranged in a light path of a light beam radiated from the semiconductor laser for over-correcting the astigmatic aberration of the light beam radiated from the semiconductor laser. The objective lens converges the light beam radiated by the light source via the optical element.