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Expired Canadian patentCanada

Digital am transmitter

CA 2128588 C · Owner: Kabushiki Kaisha Toshiba · Inventors: Miki, Nobuyuki; Yura, Haruhiko

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

A digital AM transmitter according to the invention converts a audio signal to a digital audio signal of a plurality of bits by an A/D converter, outputs a logical code signal of "1" from each of those output terminals of a code unit, whose number corresponds to the digital value of the digital audio signal, selectively generates driving signals from those output terminals of a code shifter which are equal in number to the logical code signals of "1" from the code unit, while changing the driving-signal-generating output terminals of the code shifter from one to another (or some to others) with the lapse of time, selectively guiding, with the use of carrier wave switches, those portions of …

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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 July 21, 1994 and granted November 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 21, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 21, 2016.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 21, 1994
GrantedNovember 24, 1998
Term endedJuly 21, 2014
Patent numberCA 2128588 C
Classification (IPC)H04L27/04

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedJuly 21, 1994Patent grantedNov 24, 1998Term endedJuly 21, 2014

Sources & verification

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