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Expired Canadian patentCanada

Color image-forming photographic reversal element with improved interimage effects

CA 1297717 C · Owner: Thomas, Regis · Inventors: Pfaff, Maurice; Thomas, Regis

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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 Disclosure A reversal photographic element comprising at least two dye image-forming units, at least one unit comprising, (1) a first silver halide emulsion layer spectrally sensitized to a given region of the spectrum with which is, associated a dye image-forming chromogenic coupler and, (2) a second silver halide emulsion layer spectrally sensitized to a different, region of the spectrum than the first and containing an interimage, effect-forming means such as a development inhibitor-releasing coupler, which forms either a colorless compound or a dye which does not substantially take, part in the formation of the image.

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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 March 24, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 24, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 27, 1986
GrantedMarch 24, 1992
Term endedMarch 24, 2009
Patent numberCA 1297717 C
Classification (IPC)G03C1/46 +2 more

Timeline

Timeline From CIPO dates

19871990199319961999200220052008Application filedOct 27, 1986Patent grantedMarch 24, 1992Term endedMarch 24, 2009

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