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. 18, 1984
Filed:
Feb. 09, 1982
Donald L Ort, Dallas, TX (US);
Xerox Corporation, Stamford, CT (US);
Abstract
An optical position encoder system comprising a circuit for removing the electrical bias usually associated with the optical sensor outputs, and for generating a voltage output varying with the encoder position to produce an indication of angular or linear displacement between zero crossings is described. In one portion of the circuit, sensor output signals 180 degrees out of phase are subtracted to automatically cancel the bias. In another portion of the circuit, signals 90 degrees out of phase are used to generate a voltage, the amplitude of which is a function of the grid position between grid zero crossings. To accomplish these results, two or more angularly displaced grids are required.