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:
Sep. 10, 1985
Filed:
Jan. 28, 1983
Timothy M Minerd, Pittsford, NY (US);
Robert E Crumrine, East Rochester, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A high contrast ratio sensor is provided by introducing a pair of photodetectors into the sensor circuitry. One of the detectors is a diffuse detector and the other is either a reflective or transmittance detector. The two photodetectors are connected in a manner to cause the diffuse detector output to subtract from the reflective (or transmissive) detector output. This subtraction of signals provides a high contrast ratio. In a first embodiment, a diffuse detector and a reflectance detector are located on the same side of the paper as the emitter light and in a second embodiment a diffuse detector and a transmittance detector are located on opposite sides of the paper to be sensed.