Autofocus system
CA 2002586 C · Owner: Nedvidek, Francis J. · Inventors: Nedvidek, Francis J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Autofocus apparatus for use in an optical system utilizing a recording medium formed from a birefringent medium and a radiation-sensitive medium. The autofocus apparatus automatically focuses radiation through the birefringent medium and substantially at the interface between the birefringent medium and the radiation-sensitive medium and includes a source of linearly polarized radiation, a quarter-wave plate to convert the linearly polarized radiation to circularly polarized radiation, and an actuator controlled lens for focusing the radiation onto the recording medium whereby radiation reflected from the first surface of the birefringent medium and the interface between the birefringent …
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 9, 1989 and granted February 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 9, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 9, 2011.
- 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.