Ultra-short wavelength photoelectric smoke detector
CA 2367049 A1 · Owner: Venzant, Kenneth L. · Inventors: Johnston, Derek Scott; Duran, Edward C.; Brooks, Floyd E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A photoelectric smoke detector incorporates a short wavelength radiant energy emitter (14). The emitter, an LED or laser diode emits frequencies in a range , of 430 to 450 nanometers. The emitted frequencies can be further shortened by directing them to impinge on a non-linear crystalline material (22). Radiant energy emitted from the material will have a wavelength on the order of sixty percent that of incident radiant energy (14'). The short wavelength energy will be scattered by airborn particulate matter characteristic of relatively fast, flaming fires. The emitter, an LED or laser diode can include an 880 or 940 nm wavelength coupled with shorter wavelength ranges (190-450 nm) …
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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 March 3, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 3, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 3, 2022.
- 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.