Method for the polishing and finishing of optical lenses
CA 2133259 A1 · Owner: Minnesota Mining And Manufacturing Company · Inventors: Follensbee, Robert A.; Lindholm, Gene O.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for polishing an optical quality surface such an ophthalmic lens, to finish which can accept a hardenable protective coating without using an abrasive slurry or gel, including the steps of: (a) providing an optical lens having a first major surface the first, major surface having an initial Rtm value of greater than 0.35 micrometers; (b) bringing the first major surface into a frictional contacting relationship with an abrasive article, wherein the abrasive article includes a sheet-like structure having deployed on at least one major surface thereof a plurality of individual abrasive composites, each composite having a plurality of abrasive particles dispersed in a binder; and (c) …
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 September 29, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 29, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 29, 2016.
- 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.