Laser assisted demolding of ophthalmic lenses
CA 2106328 C · Owner: Johnson & Johnson Vision Products, Inc. · Inventors: Davis, Thomas G.; Ross, Denwood F.; Walker, Craig W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Described is an apparatus and method for removing a molded ophthalmic lens from between the mold portions in which it is produced. A source of intense electromagnetic radiation, preferably a carbon dioxide (CO2) laser of about 80 Watts at a wavelength of 10.6 µm, is applied to at least one of the mold portions. The exposure of the mold portion to the laser is between one half and one second. Differential expansion of the heated mold polymer relative to the cooler polymer shifts one surface with respect to the other, and the shear force :breaks the polymerized lens\polymer mold adhesion and assists in the separation of mold portions. The greater the temperature gradient between the surfaces …
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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 16, 1993 and granted November 27, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 16, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 16, 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.