Diffractive, polarization modulating optical devices
CA 2553980 C · Owner: Ezra, David · Inventors: Ezra, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical device comprises an encoding surface having a micro-relief pattern (22) over at least part thereof designed to produce a predetermined diffracted first image when illuminated in use, and an optically anisotropic layer (26) such as a polymerised liquid crystal provided whereby at least part of said micro-relief pattern (22) induces local orientation of said optically anisotropic layer (26) thereby to impose a predetermined polarization modulation, thereby to produce a predetermined polarization dependent second image when illuminated in use.
Read the whole patent
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 January 19, 2005 and granted April 1, 2014. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 19, 2025.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- 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.