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. 29, 1982
Applicant:
Inventors:
John R Flint, Barrington, IL (US);
Robert F Johnston, Wildwood, IL (US);
Assignee:
Bell & Howell Company, Chicago, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
2502 / ; 2521 / ;
Abstract
A method and system for automatically calibrating a D.C. transducer are described in the environment of an illustrative film retrieval system. In this system, the output of a transducer such as a light sensor is amplified and the amplified output is compared to upper and lower limits within which it is desired to hold the transducer's amplified output. When either of the limits is exceeded, the amplification of the transducer's output is varied so as to shift its average value to a value which is between the upper and lower limits.