Polarizerless magneto-optic speed and torque sensor
CA 2125766 C · Owner: Rudd, Robert E. · Inventors: Rudd, Robert E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A polarizerless optic sensor is provided that uses a random domain magnetooptic film and a modulated normal magnetic field to vary or modulate the energy distribution in a diffraction pattern. Light is transmitted through the film and is diffracted according to a domain duty cycle so that the center beam intensity is a function of the Faraday rotation angle of the material and the intensity of the applied normal magnetic field. The polarizerless sensor can be used to realize a speed and torque sensor an, optical switch, a magnetic field sensor and many other types of devices. The invention can be used with polarized and unpolarized input light. The sensor can be implemented using a …
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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
- Filed November 30, 1992 and granted October 28, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 30, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 30, 2014.
- 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.