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.:

US 8213270 B1

PDF
Full Text
Expired
Date of Patent:
Jul. 03, 2012

Filed:

Mar. 04, 2005
Applicant:

Seiya Yamada, Hamamatsu, JP;

Inventor:

Seiya Yamada, Hamamatsu, JP;

Assignee:

Yamaha Corporation, Hamamatsu-shi, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/125 (2012.01);
U.S. Cl.
CPC ...
Abstract

In an optical disk recording apparatus, a monitor monitors a recording power of a laser light. A laser control circuit enables a laser diode to perform test recording while using the monitor to monitor the recording power of the laser light and while controlling a laser drive voltage, so that the monitored recording power reaches a given reference value during the test recording. A voltage measurement section measures the laser drive voltage when the recording power of the laser light reaches the reference value. A calculation section calculates an initial laser drive voltage from the reference value of the recording power and the measured laser drive voltage corresponding to the reference value. A main controller allows the laser control circuit to set the calculated initial laser drive voltage and to start the recording while supplying the laser control circuit with the target value so that an actual recording power of the laser light promptly reaches the target value during the course of the recording.


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