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. 04, 1987
Filed:
Jun. 30, 1986
Applicant:
Inventors:
Masami Emoto, Yokohama, JP;
Hideo Inuzuka, Yokohama, JP;
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
250201 ; 369 45 ;
Abstract
A knife edge type focus detection method for optics associated with an optical pickup is disclosed. A light intercepting member is interposed between an object lens and a light receiving element for focus detection in order to cut 60-95% of a reflected flux for focus detection before the flux reaches the light receiving element. The intercepted part of the flux includes a light ray which propagates through the optical axis of the optics.