Indirect ophthalmoscopy lens system and adapter lenses
CA 2176385 C · Owner: Volk, Donald A. · Inventors: Volk, Donald A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention is directed to an ophthalmoscopic or gonioscopic lens system (10) as well as an adapter lens system for use with such an associated lens apparatus. The indirect ophthalmoscopy lens of the invention for use in examination or laser treatment of a patient's eye (16) comprises a hand-held pre-set or, fixed system having at least two lens elements each having first and second surfaces. At least one of the lens elements includes an aspheric surface of revolution. The at least two lens elements are positioned adjacent one another in a housing, such that the refractive properties of each are combined to converge light from an illumination light source to the entrance pupil (18) of the …
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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 November 10, 1994 and granted June 13, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 10, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 10, 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.