Digital exchange and its control method
CA 2006452 C · Owner: Ohtsuka, Eiji · Inventors: Ohtsuka, Eiji; Ikemori, Kimio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A digital exchange which can prevent its failure even when an abnormality takes place in one of digital trunks extracting clock signals from digital lines so long as at, least one of the digital trunks is normal and also a, method of controlling the digital exchange. A common transmission line is used for the clock signals extracted at the digital trunks, a synchronizing-signal generating circuit is provided for generating a synchronizing signal having a predetermined period with use of the clock signal received from one of the digital trunks through the common transmission line, and the clock extracting circuit in each of the digital trunks is provided with a circuit for sending the …
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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 December 21, 1989 and granted June 18, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 21, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 21, 2011.
- 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.