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:
Jul. 18, 2006
Filed:
Feb. 19, 2003
Yuichi Maekawa, Atsugi, JP;
Yuichi Maekawa, Atsugi, JP;
Mitsumi Electric Co., Ltd., Tokyo, JP;
Abstract
An optical power level-controlling device controls optical power level of a laser beam irradiated on an optical disk. The optical power level takes an ERASE (reference) level, a lower BIAS level and a higher WRITE level. Recording is performed by alternating the optical power level between BIAS and WRITE levels. In a controlling part, test signals are recorded while varying the optical power level and in an OPC for setting an optimum WRITE level by reproducing the test signals. A combined control, i.e., combination of a feedback control and a fixed value control at a predetermined ratio, is performed on BIAS level during a recording operation of the test signals. Fixed value control is performed on the difference between ERASE level and BIAS level during a recording operation.