Method for tinting a hydrophilic contact lens
CA 2102550 A1 · Owner: Ciba-Geigy Ag · Inventors: Stebbins, Leslie F.; Turek, Richard C.; Janssen, Robert A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, A method of tinting an unhydrated contact lens involves the steps of providing an unhydrated contact lens; providing a dyestuff solution; providing a printing block comprising a hydrophilic polymer material containing a dye complexing agent capable of noncovalently bonding the dyestuff; placing the dyestuff solution onto the printing block; contacting the unhydrated contact lens and the printing block for a time sufficient to allow the dyestuff solution to diffuse to the lens; and removing the lens from the printing block. (Fig. 1)
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 November 5, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 5, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 5, 2015.
- 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.