Radio frequency automatic identification system
CA 2119774 C · Owner: American Product Development Corporation · Inventors: Greene, Morton
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A radio frequency automatic identification system detects targets which include solid resonators (12) resonating at several frequencies, attributing information to the frequencies at which the target resonates. Preferred resonators are quartz crystals, which may be made by a process of heating quartz to soften it and cutting crystals to approximate size and resonant frequency. Resonators produces by such a process are measured to determine their actual resonant frequency and preferably, the crystals are sorted into predetermined frequency windows in accordance with their measured resonant frequency. A set of resonators (12a-12n) having frequencies corresponding to predetermined data is …
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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 24, 1992 and granted February 23, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 24, 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.