Polarizing plastic optical device and process for producing the same
CA 2563763 C · Owner: Kato, Sumio · Inventors: Kato, Sumio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A polarizing plastic lens comprising a polarizing film with low tendency to detachment from an optical resin layer. There is provided polarizing plastic lens (11) comprising polarizing film (13) constituted of a polyvinyl alcohol resin. Two optical resin layers (12a,12b) of different thicknesses may be disposed on both surfaces of the polarizing film (13). The optical resin layers (12a,12b) are formed by polymerizing a polymerization raw material composition in contact with the polarizing film (13). The polymerization raw material composition contains as one main component an isocyanated or isothiocyanated compound. The isocyanate or isothiocyanate group reacts with the hydroxyl of …
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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 February 18, 2005 and granted October 14, 2014. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 18, 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.