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Expired Canadian patentCanada

Facsimile transmitter having improved response

CA 1099391 A · Owner: Exxon Research And Engineering Company · Inventors: Nelson, Richard L.

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 facsimile transmitter detects dark-light variations in an illuminated document by means of a photodetector. Fiber optics form an optical pathe from the illuminating means to the document and from the document to the photodetector means with filter means being located in the optical path for attenuating light in the near infrared region of the spectrum. Amplifier means are coupled to the photodetector Means and automatic gain control means are associated with the amplifier means for increasing the gain of the amplifier in response to a lesser amount of light detected by the photodetector. The gain control means is adjustable so as to limit the increase in gain when detecting dark regions. …

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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 14, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 14, 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.
FiledJune 17, 1976
GrantedApril 14, 1981
Term endedApril 14, 1998
Patent numberCA 1099391 A
Classification (IPC)H04N1/40 +1 more

Timeline

Timeline From CIPO dates

19771980198319861989199219951998Application filedJune 17, 1976Patent grantedApril 14, 1981Term endedApril 14, 1998

Sources & verification

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