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:
Apr. 06, 1982
Filed:
May. 30, 1980
Applicant:
Inventor:
Joachim Proske, Brunswick, DE;
Assignee:
Rollei-Werke Franke & Heidecke GmbH & Co., Brunswick, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
362 17 ; 362 18 ; 362276 ; 362280 ; 362308 ; 362318 ;
Abstract
The angular distribution of illumination passing through a selectively diffusing element can be varied by placing the diffusing element in a reflector unit so that the diffusing element is in the path between a light source and the object to be illuminated. A variable diffuser can comprise a liquid-crystal cell driven by a variable voltage to control the amount of diffusion by the reflector unit. The control voltage can be set in accordance with change in focal length in a zoom lens of a camera using the light source and reflector unit as a flash gun.