Extended temperature range polymer dispersed liquid crystal light shutters
CA 2031464 A1 · Owner: West, John L. · Inventors: West, John L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An extended temperature range polymer dispersed liquid crystal light shutter electrically switchable between a transmissive and an opaque state over a working temperature range of about -40°C to about 100°C. The shutter includes a polymer-dispersed liquid crystalline (PDLC) material comprising a fairly highly cross-linked transparent matrix having phase-separated microdroplets of liquid crystal dispersed therein the, liquid crystal existing in a supercooled liquid crystalline state at low temperatures. Such light shutters are employed in various windows and electrooptic displays, wherever it is desirable to be able to adjust visible or transparency and regardless of temperature extremes.
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 December 4, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 4, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 4, 2012.
- 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.