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:
Dec. 24, 2002
Filed:
Dec. 08, 1999
Shinya Yoshida, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
In a light detecting device for detecting light beams passing through a light-gathering optical system, an aberration detector of the present invention includes photodetectors for forming a light-gathering spot of a first light beam passing near an optical axis, and photodetectors for forming a light-gathering spot of a second light beam passing outside the first light beam. In accordance with detection signals of the detectors, a spherical aberration of the light-gathering optical system can be detected. With this arrangement, a spherical aberration appearing on the light-gathering optical system is precisely detected and corrected in an appropriate manner, so that it is possible to suitably record and reproduce information in a magneto-optical disk.