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. 19, 1980
Filed:
Aug. 15, 1978
Applicant:
Inventor:
Ernst Biedermann, Taufkirchen, DE;
Assignee:
AGFA-Gevaert, A.G., Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
355 56 ; 352140 ; 354 25 ; 355 74 ;
Abstract
A photographic copying apparatus wherein a composite mask is installed between the plane of photographic paper and a variable-focus optical unit which images a light source or an original into the plane of photographic paper. The movable sections of the mask carry pairs of photodiodes. A control unit adjusts the optical unit when the latter projects light onto both photodiodes of each pair in a direction to reduce the projected image and in the opposite direction when none of the photodiodes are illuminated. The adjustment is terminated when the size of the projected image is such that only one diode of each pair is illuminated.