Polarization converting device and polarized-light illuminating system using the device and image display unit using the same
CA 2042829 C · Owner: Canon Kabushiki Kaisha · Inventors: Kawasaki, Shigeru; Mitsutake, Hideaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A polarization converting device for converting a light from a light source into a polarized light comprises a first prism having a first slant plane for receiving the light from the light source and dividing it into first and second lights with their polarized planes orthogonal, a first emergent surface from which the first light exits, and a second emergent surface from which the second light exits, a second prism having an incident surface opposed to the second emergent surface of the first prism, a second slant plane for reflecting and deflecting the second light from the incident surface so as to direct it to an optical path almost parallel to that of the first light, and a third …
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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 May 17, 1991 and granted December 2, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 17, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 17, 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.
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.