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. 28, 2004
Filed:
Feb. 25, 2002
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 ;
U.S. Cl.
CPC ...
G11B 7/00 ;
Abstract
A means for measuring the temperature in the surroundings of a semiconductor laser is provided and, if the temperature is not above a certain level, power correction is performed at high speed by linearly approximating the I-H characteristic according to one item out of reproduction power and multi-pulse recording power, or if the temperature is higher, accurate power correction of the semiconductor laser is accomplished by detecting a plurality of items out of reproduction power and multi-pulse recording power.