Signal sending control system
CA 1063271 A · Owner: Fujitsu Limited · Inventors: Satake, Yasuo; Ogawa, Kenichi; Kanzaki, Hisao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A signal sending control system for use in a telephone system which employs telephones having a bell for calling and an exchange employing a speech network composed of electronic switches. The signal sending control system includes a ringing signal sending circuit having a signal source for generating n continuous ringing signal and interrupting means for controlling sending of the ringing signal generated from the signal source. A switching device is provided for each subscriber's line for connecting the telephone to the speech network or to the ringing signal sending circuit. A control device individually controls the switching device of the subscriber's line in accordance with control …
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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
- Granted September 25, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 25, 1996.
- 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.