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:
Oct. 30, 1984
Filed:
Mar. 04, 1983
Applicant:
Inventors:
Kunio Aiki, Hachiouji, JP;
Masahiro Ojima, Kokubunji, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369122 ; 369107 ; 372 43 ;
Abstract
An optical pickup wherein a semiconductor laser device for projecting a laser beam onto an optical disc is driven by a D.C. current and a high-frequency current superposed thereon, and the laser device oscillates in a multiple longitudinal mode.