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:
Oct. 16, 2001
Filed:
Mar. 12, 1999
Kenji Nagashima, Suita, JP;
Yasuhiro Tanaka, Ashiya, JP;
Tetsuo Saimi, Hirakata, JP;
Yoichi Saito, Hirakata, JP;
Yasuo Nishihara, Katano, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In an optical head, two object lenses,fixed to a lens holder,are provided to serve as means for condensing a light beam,wherein these object lenses,are at positions eccentric from a support axis,The object lenses,and,are fabricated to satisfy prescribed conditions to suppress aberration. When either object lens,or,is selected for an optical recording medium,degrading of signals can be prevented. Alternatively, two light sources,are provided for one object lens,, and the object lens is fabricated to satisfy prescribed conditions to suppress aberration. When either one of the light sources is used, degrading of signals can be prevented. In a different optical head, a recording medium,is set on a disk driving device,and an optical head,is provided movable freely in radial directions. The tilt of the recording medium is detected with a sensor, and the optical axis of the beam is controlled according to the detected tilt to cancel aberration.