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:
Oct. 16, 2001
Filed:
Mar. 08, 1999
Taku Ito, Tokyo, JP;
Masato Noguchi, Saitama, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A viewing optical instrument has a roof prism which is provided with a pair of reflection surfaces intersecting at a nominal face angle of 90°, wherein the pupil is split by an edge line of the reflection surfaces of the roof prism. The reflection surfaces are provided with a multiple-layer coating which does not absorb visible light. A change in the phase difference produced between light incident on one of reflection surfaces located on opposite sides of an edge line of the roof prism and emitted from the other reflection surface, and light incident on the right reflection surface and emitted from the left reflection surface is restricted to reduce wavefront aberrations to thereby improve the quality of an image to be viewed. A roof prism used in the optical instrument is also disclosed.