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:
Nov. 06, 2001
Filed:
Dec. 30, 1999
Hiroyasu Ozaki, Tokyo, JP;
Takayuki Ito, Saitama, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A viewfinder optical system of a single-lens reflex camera has a photographic optical system and an image plane positioned on an optical axis of the photographic optical system. The system includes a first optical member positioned between the photographic optical system and the image plane, the first optical member bending the optical axis of the photographic optical system to define a viewfinder optical axis of the viewfinder optical system. A second optical member bends the viewfinder optical axis at least once to make the viewfinder optical axis that extends parallel to the optical axis of the photographic optical system. A third optical member, having substantially no optical power, is positioned on the viewfinder optical axis extending parallel to the optical axis of the photographic optical system. The third optical member is made of a transparent material having a refractive index higher than the refractive index of air. An eyepiece is positioned behind the third optical member on the viewfinder optical axis.