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. 18, 1992
Filed:
Oct. 13, 1989
Applicant:
Inventors:
Tetsuo Kyogoku, Osazaki, JP;
Katsuhiko Takeda, Toyokawa, JP;
Assignee:
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G03B / ;
U.S. Cl.
CPC ...
359588 ; 359589 ; 359587 ; 355 71 ;
Abstract
An interference film filter for use in a copying machine as mounted on an optical path of light traveling through an image-forming lens for preventing transmission of the light in a predetermined wavelength range. The filter comprises a transparent glass substrate, and interference films each consisting of a plurality of layers formed by vapor deposition on the substrate. The interference films include a film disposed centrally of the substrate, and an opposed pair or pairs side films. Each of the side films has a greater optical film thickness than the center film or a film disposed immediately inwardly.