Aspheric plano eyewear
CA 2225823 C · Owner: Hall, James · Inventors: Desy, Raoul; Hall, James; Hasenauer, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A novel plano lens and eyewear incorporating such lens is presented wherein the plano lens comprises a front surface curvature which is created by rotating an aspheric shape about an axis which is offset from an axis of the aspheric shape. In a preferred embodiment the aspheric shape is an ellipse or , at least is an aspheric shape a segment of which has an elliptical arc. This elliptical arc is rotated about an axis spaced (offset) some distance from a major or minor axis of the ellipse. In a more preferred embodiment the , ellipse is rotated about an axis spaced from and parallel to the major or minor axis of the ellipse, but in the same plane as the ellipse. The resulting surface …
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 24, 1997 and granted September 28, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 24, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 24, 2019.
- 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.