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. 28, 1990
Filed:
Mar. 10, 1989
Victor D Loewen, San Jose, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An optical shaft angle encoder has a code wheel with alternating reflective and non-reflective areas in a circumferential path on one face of the wheel. A light emitting diode is spaced apart from the reflective areas on the wheel. Four photodetectors are also spaced apart from the same face of the wheel so that, as the wheel rotates, the photodetectors are alternately illuminated or not illuminated by light from the light emitting diode that is reflected from the reflective areas. Preferably the light emitting diode is relatively nearer the shaft axis than the photodetectors and is in a radial direction from the shaft axis which bisects the array of photodetectors.