Optical d.c. voltage transformer
CA 2038004 C · Owner: Sato, Tadashi · Inventors: Takahashi, Genji; Sato, Tadashi; Seino, Kazuyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical d.c. voltage transformer having an electrooptic medium to which a d.c. electrical field or voltage to be measured is to be applied. The electrooptic medium is adapted for affecting the polarized light from the polarizer by an electrooptical effect to a degree proportional to the strength of the electrical field or voltage. The transformer comprises a photodetector for producing an optical signal proportional to the affected light received from the electrooptic medium, a device for converting the optical signal from the photodetector into an electrical signal a chopper for pulsating, the electrical field or voltage to be applied to the electrooptic medium, in terms of time, 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 March 11, 1991 and granted October 11, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 11, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 11, 2013.
- 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.