Optical encoder with two photosensors
CA 1262269 C · Owner: Martell, Dennis J. · Inventors: Martell, Dennis J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical encoder for indicating revolutions of a shaft includes two phototransistors positioned to be energized concurrently by light from a light source a barrier rotated by the shaft to shade the photosensors from the light source during a portion of each revolution and a signal processing circuit which responds to outputs of the photosensors when both are illuminated to provide an unambiguous indication at the end of each revolution of the shaft. The signal processing circuit includes a latch circuit which is set in response to one photosensor providing an output while the other photosensor is providing its output. The latch circuit is reset when the outputs from both photosensors …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted October 10, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 10, 2006.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.