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:
Nov. 15, 1977
Filed:
Jun. 03, 1975
Applicant:
Inventor:
Alois Rieder, Munich, DT;
Assignee:
AGFA-Gevaert, A.G., Leverkusen, DT;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
354 44 ; 354 / ; 354 42 ; 354 43 ; 354 / ;
Abstract
A bridge circuit which includes a photoelectric transducer furnishes input signals to a differential amplifier whose analog output signal varies in correspondence to the bridge unbalance. A first and second bistable threshold circuit changes the analog output signal into digital signals signifying bridge unbalance in a first direction, balance, and unbalance in the opposite direction, a motor is energized to rotate in a direction corresponding to the direction of bridge unbalance. The motor can be utilized to move the objective lens of a slide projector or change the aperture of a diaphragm.