Intermediate frequency receiver apparatus
CA 2124878 C · Owner: Vtech Communications Ltd. · Inventors: Dormer, Michael William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A transmitting and receiving system having two or more radios, each capable of transmitting and receiving a transmission signal on two or more radio frequencies where a first radio transmits on a selected frequency at a predetermined time interval and a second radio recovers the transmitted signal. The second radio has a first intermediate frequency generator which generates an intermediate frequency signal which is substantially equal to an integer multiple of the channel spacing whereby an image response corresponding to the selected frequency is separated by twice the intermediate frequency signal from the selected frequency. Thus locations for the two or more transmission frequencies …
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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 June 1, 1994 and granted July 23, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 1, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 1, 2016.
- 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.