Liquid crystal display employing dual negative retarders and a brightness enhancing film
CA 2222313 C · Owner: Silverstein, Louis D. · Inventors: Silverstein, Louis D.; Crawford, Gregory P.; Fiske, Thomas G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A transmissive, backlit color twisted-nematic or super-twisted-nematic liquid crystal display employing a front fiber-optic faceplate or optical equivalent as a front retaining element of a liquid crystal cell that increases viewing angle between the display and a viewer while minimizing or eliminating undesirable variations in luminance, contrast ratio and chromaticity is described. The fiber-optic faceplate or optical equivalent includes cylindrical optical features and interstitial cladding material of greater optical index than the cylindrical optical features. The interstitial cladding material may include an opaque mask blocking layer to prevent the interstitial apertures from …
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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 26, 1997 and granted April 3, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 26, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 26, 2019.
- 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.