Open transmission line locating systems
CA 2044246 C · Owner: Instantel Inc. · Inventors: Harman, Robert Keith
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An open transmission line system for locating am entity (110) moving along a defined pathway uses transmissions from a remote, independent transmitter (106), conveniently a commercial radio or television station. The system comprises two receivers, both tuned to the frequency of the transmission. One receiver (101) receives signals directly from the transmitter (106) by means of an antenna 104. The other receiver (102) receives the signal from the transmitter (106) by way of an open transmission line (107). A processor (103) processes the signals from the two receivers to detect the entity. The system may use transmissions at different frequencies from plural mutually-spaced transmitters …
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 February 20, 1991 and granted July 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 20, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 20, 2013.
- 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.