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. 16, 2002
Filed:
Sep. 09, 1999
Tsutomu Maruyama, Chiba, JP;
Sony Corporation, Tokyo, JP;
Abstract
According to the present invention, a semiconductor laser drive device is provided with a high-frequency superimposing circuit to superimpose a high-frequency current on a laser diode and a superimposed frequency changing circuit to change the superimposed frequency and the amplitude of high-frequency current responsive to an operation mode of an optical disk device, wherein the respective superimposed frequency and the amplitude between at least a first output power and a second output power from the semiconductor laser are changed in response to the operation mode of the optical disk device. This not only enables the high-frequency superimposition of a plurality of frequencies and the mode optimization but also facilitates the reduction of laser noises.