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Expired Canadian patentCanada

Bi-directional catv data transmission and control system

CA 1138070 A · Owner: Cablebus Systems Corporation · Inventors: Gumm, Linley F.; Schrock, Clifford B.

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Abstract of the Invention, A bi-directional data transmission and control system utilizing a central processing unit and a multiplicity of remote subscribers. Each subscriber is provided with a terminal coupled with the central processing unit by a suitable medium such as a CATV channel. Each terminal is provided with a demarcation plane separating common circuitry from a number of specialty modules and a common bus therebetween for circuitry simplification, application expandability and individual tailoring. The data transmission scheme efficiently utilizes the frequency spectrum and enhances polling frequency by permitting selective polling of any given specialty module or subscriber at …

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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 December 21, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 21, 1999.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 9, 1980
GrantedDecember 21, 1982
Term endedDecember 21, 1999
Patent numberCA 1138070 A
Classification (IPC)H04N7/10 +2 more

Timeline

Timeline From CIPO dates

1981198319851987198919911993199519971999Application filedJune 9, 1980Patent grantedDec 21, 1982Term endedDec 21, 1999

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.