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:
Aug. 16, 2005
Filed:
Mar. 16, 2001
Yuichi Kamioka, Osaka, JP;
Toshiya Akagi, Osaka, JP;
Yoshiyuki Miyabata, Kyoto, JP;
Yuichi Takahashi, Osaka, JP;
Yuichi Kamioka, Osaka, JP;
Toshiya Akagi, Osaka, JP;
Yoshiyuki Miyabata, Kyoto, JP;
Yuichi Takahashi, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A semiconductor laser driving apparatus for directing light to an optical disc for recording a recording mark based on a recording current and reproducing the recording mark to generate a reproduction signal. The apparatus includes a reproduction current generation section; a high frequency current generation section for generating a current including a high frequency component for reducing semiconductor laser noise in the reproduction; a recording current generation section, the recording current including a pulse corresponding to the recording mark and including a plurality of multi-pulses; and a current driving section for amplification. The apparatus further includes a filter to attenuate the enhanced high frequency components in the high frequency current and in the enhanced high frequency component; and a switching section for switching the filter so that the enhanced component in the recording current is superposed on at least one of the multi-pulses.