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:
Feb. 27, 1996
Filed:
Aug. 26, 1994
Kazuhiro Fujikawa, Tokyo, JP;
Nobuo Miyairi, Kanagawa, JP;
Yasuhiro Miyazaki, Tokyo, JP;
Takashi Ogata, Tokyo, JP;
Masaaki Komiya, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
In an optical data recording/reproducing apparatus for performing write and read operations of data by irradiating laser light onto an optical data recording medium, in order to reduce noise of a semiconductor laser, an HF oscillator is provided to superpose an HF current on a drive current to be applied to the semiconductor laser. The HF oscillator is housed in a conductive shield case together with the semiconductor laser. An LC low-pass filter is also provided in a signal line connecting the components inside and outside the shield case to prevent undesired radiation of the HF current. A write drive line and a read drive line of the semiconductor laser are separated in the shield case, and the write drive line is disconnected from the HF oscillator in at least a read mode.