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Expired Canadian patentCanada

Method of and apparatus for counting objects

CA 1283189 C · Owner: Varri, Alpo · Inventors: Kulju, Hannu; Varri, Alpo

CIPO record

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

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Abstract From the Canadian patent

A method of and apparatus for counting objects present within a predetermined area, by detecting acceleration and deceleration of the objects employ at least one Doppler radar to sense the movements of the objects by monitoring the Doppler frequencies of signals reflected from the objects, amplifying the Doppler signal reflected from each of the objects to provide an amplified signal, effecting an automatic gain control of the amplified signal to provide a signal of substantially constant strength independent of the distance and size of the respective object, detecting a frequency variation of the constant strength signal as an indication of change in the speed of movement of a respective …

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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 April 16, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 16, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 25, 1987
GrantedApril 16, 1991
Term endedApril 16, 2008
Patent numberCA 1283189 C
Classification (IPC)G01S13/88 +2 more

Timeline

Timeline From CIPO dates

1988199119941997200020032006Application filedMay 25, 1987Patent grantedApril 16, 1991Term endedApril 16, 2008

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