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Expired Canadian patentCanada

Charged area (cad) image loss control in a tri-level imaging apparatus

CA 2076791 C · Owner: Xerox Corporation · Inventors: Paolini, Anthony L.; Macdonald, Daniel W.; Berman, Robin E.

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 pair of Electronic Voltmeters (ESV) are utilized to control the P/R charging voltage in a Tri-Level imaging apparatus. One of the ESVs is used to control the voltage increases of a charging device. The other ESV is used to monitor the charge level of the charged area image of a Tri-Level image. When a critical value is sensed the control of the charging device is shifted to the ESV that monitors the charged area image level and limits the output from the charging device to a predetermined target value..

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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 August 25, 1992 and granted February 23, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 25, 2012.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 25, 2014.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledAugust 25, 1992
GrantedFebruary 23, 1999
Term endedAugust 25, 2012
Patent numberCA 2076791 C
Classification (IPC)G03G15/01 +2 more

Timeline

Timeline From CIPO dates

1993199519971999200120032005200720092011Application filedAug 25, 1992Patent grantedFeb 23, 1999Term endedAug 25, 2012

Sources & verification

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