Film cassette containing pre-exposed film
CA 2074009 C · Owner: Polaroid Corporation · Inventors: Kirkendall, George F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
During manufacture each frame of a film strip has one portion masked while the frame is exposed to light. Said light impinges on a second portion of the frame to form a latent image. The film strip is mounted within a camera where the previously unexposed portion of the frame is exposed to a second image bearing light while the pre-exposed portion of the frame is masked from said second light the strip of film is removed from the camera to develop the two latent images as a single photograph.
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 July 16, 1992 and granted February 22, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 16, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 16, 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.
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.