Bidirectional telewriting system operating in an alternating mode over a single carrier
CA 1114942 A · Owner: Telediffusion De France · Inventors: Dagnelie, Jean-Paul G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A bidirectional telewriting system for two-way transmission of of telewriting data over a transmission channel which is shared by a speech link. A frequency window is used within the speech frequency band, within which a single carrier is used. A commutator at each terminal causes alteration in the direction of transmission of the telewriting data over the single carrier.
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
- Granted December 22, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 22, 1998.
- 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.