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. 27, 1979
Filed:
Jan. 20, 1976
William C Turner, Northridge, CA (US);
William R Limburg, Torrance, CA (US);
John S Burton, Los Angeles, CA (US);
Terminal Data Corporation, Woodland Hills, CA (US);
Abstract
A photographic exposure control for sensing and electrically processing illumination reflected from a moving document. An opto-photoelectric pickup accepts reflected illumination having a selected spectral characteristic. Electronic analog logic; (1) samples and holds the equivalent electrical magnitude of the reflected illumination, (2) provides an electrical timing interval that is the reciprocal of the electrical magnitude, (3) arranges automatically for constant exposure of the film through an adjustable electrical ramp generator, and (4) generates an 'exposure stop' signal in a comparator that receives the ramp and the reciprocal timing information. The control signal thereby formulated typically accurately actuates a translational type shutter through a stepper motor to maintain a constant density of the background of images on microfilm for successive documents regardless of the background reflectivity thereof. A 'Manual' mode is alternately available for providing a fixed exposure, particularly for documents having unorthodox reflectivity formats.