Call related information receiver unit
CA 2265115 C · Owner: Davis, Paul Joseph · Inventors: Popa, James Charles; Johanson, James A.; Iyengar, Vasu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An adjunct Type II caller ID/call waiting (CIDCW) receiver unit is provided which has a greatly improved ability to detect tones and other call related information on a telephone line from a central office while the customer premises equipment is in an off-hook condition. The inventive adjunct CIDCW receiver unit is placed in series between the telephone line from the central office and the customer premises equipment rather than in parallel with the customer premises equipment as in conventional adjunct CIDCW receiver units. A second telephone line interface (TL1) is included in the adjunct CIDCW receiver unit for connection to the customer premises unit to simulate the impedance of the …
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 March 10, 1999 and granted September 24, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 10, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 10, 2021.
- 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.