Information display device
CA 2118702 C · Owner: Minnesota Mining And Manufacturing Company · Inventors: Bradshaw, Thomas I.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Information display device comprising a legend face (12) with a twodimensional array of individually operated pixels (14). The legend face comprises an opaque sheet having a front side (16) to be presented to an observer and a back side (18). Each pixel comprises an aperture (22) in the opaque sheet and an associated shutter (24), the aperture being partially-light-transmissive and preferably retroreflective, the shutter being opaque and having first and second faces which are of visually distinctive appearance with the second face being retroreflective. Each shutter is selectively settable to a first state in which it occludes its associated aperture such that the first face (26) of …
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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 September 15, 1992 and granted August 5, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 15, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 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.