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.

Date of Patent:
Nov. 23, 1999

Filed:

Sep. 29, 1997
Applicant:
Inventors:

Tatsuaki Sakurai, Kanagawa-ken, JP;

Ryuji Kudo, Kanagawa-ken, JP;

Masaaki Sofue, Machida, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 54 ; 369 58 ; 369116 ;
Abstract

A layer beam controller for an optical storage apparatus includes a laser beam generator, a laser beam power varier for varying the laser beam power to first, second, and third power levels, a memory for storing predetermined reference values including first reference values corresponding to the first power level and second reference values corresponding to the second power level, a light amount detector for detecting a light amount of the laser beam, a laser beam power corrector for correcting the laser beam power at the respective power level by comparing the light amount and a corresponding one of the predetermined reference values selected by a type of the compact disk in operation in the optical storage apparatus. The laser beam controller further includes a power level assigner for assigning the first, second and third power levels based on the type of disk.


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