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:
Mar. 22, 1988
Filed:
Jun. 24, 1985
Hiroaki Hoshi, Kawasaki, JP;
Naosato Taniguchi, Yokohama, JP;
Kiyonobu Endo, Yokohama, JP;
Tetsuro Kuwayama, Yokohama, JP;
Hiroshi Osawa, Yokohama, JP;
Yasuo Nakamura, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Canon Denshi Kabushiki Kaisha, Saitama, JP;
Abstract
An optical head device comprises a light source, condensing optics for condensing a light beam emitted from the light source on an optical recording medium, a photodetector for detecting the light of the light beam reflected from the recording medium, and a beam splitter having a diffraction grating arranged in the optical path of the light beam entering the recording medium from the light source along a plane substantially perpendicular to the optical axis of the incident light beam to cause the light reflected light from the recording medium to be diffracted by the diffraction grating and directed to the photodetector.