Expired Canadian patentCanada
Small aperture multifocal
CA 2014754 C · Owner: Cohen, Allen L. · Inventors: Cohen, Allen L.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical device suitably employable in intraocular and contact lenses that employs a phase zone plate of a Cohen lens design that relies on a small number of zones to provide multifocal images.
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 April 18, 1990 and granted December 29, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 18, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 18, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 18, 1990
GrantedDecember 29, 1998
Term endedApril 18, 2010
Patent numberCA 2014754 C
Classification (IPC)G02C7/06 +2 more
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.