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. 10, 1992
Filed:
Feb. 01, 1991
Katsuhiko Nozaki, Tokyo, JP;
Tetsuya Abe, Tokyo, JP;
Asahi Kogaku Kogyo K.K., Tokyo, JP;
Abstract
A Kepler-type erect image viewfinder includes a first prism having an emergent surface being formed of a spherical or an aspherical surface and having a positive power. A second prism has an incident surface being formed of a spherical or aspherical surface and also having a positive power. The emergent surface of the first prism is spaced apart from the incident surface of the second prism, with an image-forming plane being positioned closer to the incident surface of the second prism than the emergent surface of the first prism. This arrangement enhances image magnification and compensates for field curvature, while simultaneously allowing for the viewfinder to have a reduced overall length.