Optically variable interference device with peak suppression and method
CA 2048564 C · Owner: Phillips, Roger W. · Inventors: Coombs, Paul Graham; Phillips, Roger W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Optical variable interference device with peak suppression having a reflector with first and second surfaces. A thin film multilayer interference stack is disposed on the first surface. The interference stack is comprised of at least two periods with each period being comprised of a metal absorber layer and a dielectric spacer layer.
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 August 7, 1991 and granted October 23, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 7, 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.
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.