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. 24, 1982
Filed:
Apr. 03, 1980
Robert W Kachelries, West Goshen, PA (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A film processor having film transport rollers driven by a drive motor, a sensor for generating a signal representative of roller transport speed and a film density detector arrangement that includes a photodetector responsive to the intensity of a light source for generating a reference background level signal against which processed film is compared is characterized by a monitoring arrangement which periodically samples the photodetector output signal and adjusts a reference background level signal in accordance with fluctuations in the output of the scanner arrangement. To prevent the system from reacting to momentary perturbations in background level a moving weighted averaging technique is employed. The rate at which the reference background level signal is sampled is determined by the transport roller speed.