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. 10, 1984
Filed:
Mar. 26, 1982
Claude Thebault, Meylan, FR;
Kis France, Grenoble, FR;
Abstract
A subtractive filter having three elementary filters, each comprising a fixed cylindrical central portion having at its center a channel for the passage of the light and on its surface a radial milled slot; a rotary ring concentric to the said fixed cylindrical central portion having a graduation on its central periphery, the inside of said rotary ring having the shape of a logarithmically progressive ramp; and a filter holder comprising a frame adapted to slide in the said radial milled slot in the fixed cylindrical central portion, the bottom of said frame having the shape of a rounded point which rests against said ramp and the top of said frame having a spring resting against a part fastened to the periphery of the fixed central portion, said frame of said filter holder comprising at its top a window opening and at its bottom the filter. Regulation of light passing through each of the three filters is accomplished by rotating the rotary rings.