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:
Jul. 30, 1991
Filed:
Dec. 21, 1989
Hitoshi Kageyama, Azuchi, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
An interference filter for use in a copying machine comprises a glass substrate and a plurality of high-refractive index and low-refractive index layers alternately superposed on the substrate for reducing ripples at opposite sides of the reflective range. The first and second layers counted from the substrate have a greater optical layer thickness than .lambda.o/2. The third and fourth layers have a greater optical layer thickness than .lambda.o/4. The second top layer has a greater optical layer thickness than .lambda.o/2. The top layer has a smaller optical layer thickness than .lambda.o/4. The remaining layers have an optical layer thickness equal to .lambda.o/4.