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. 23, 1999
Filed:
Jan. 08, 1997
Applicant:
Inventor:
Keiji Osawa, Tokyo, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
396106 ; 396109 ; 396114 ;
Abstract
A focus detection device that is capable of performing focus detection in several focus detection areas within a photographic image plane using, for example, a phase difference method and that uses an auxiliary illumination light with at least one of the areas also includes infrared light cut filters that block the transmission of light above predetermined wavelengths. In particular, the maximum wavelength of the light transmitted by the infrared cut filter for one of the focus detection areas is different than the maximum wavelength of the light transmitted by the infrared cut filter for another one of the focus detection areas.