Variable pitch structured optical film
CA 2251252 C · Owner: Cobb, Sanford Jr. · Inventors: Kotchick, Keith M.; Hibbard, William A.; Cobb, Sanford Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention includes a structured optical film with variable pitch peaks and/or grooves to reduce the visibility of moiré interference patterns and optical displays incorporating one or more layers of the film. The pitch variations can be over groups of adjacent peaks and/or valleys or between adjacent pairs of peaks and/or valleys.
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 March 3, 1997 and granted February 5, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 3, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 3, 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.