Rectilinear photokeratoscope
CA 2080668 C · Owner: Visx, Incorporated · Inventors: Munnerlyn, Charles R.; Shimmick, John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A rectilinear keratoscope for determining the curvature of the anterior corneal surface of an eye. The keratoscope includes a translucent sheet having a curved pattern in the shape of a grid of intersecting individual, curved lines. The pattern forms a substantially rectilinear grid image when reflected from a curved surface having a known radius of curvature. Deviations from a spherical surface can be qualitatively and quantitatively determined from examining the nature of the reflected image pattern and by measuring the spatial frequency of grid lines lying between a reference point and an image point corresponding to a point on the surface of the cornea whose refractive power is to be …
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 October 15, 1992 and granted December 16, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 15, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 15, 2014.
- 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.