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Expired Canadian patentCanada

Process for the preparation of photographic color copies

CA 2050807 C · Owner: Gretag Systems, Inc. · Inventors: Kraft, Walter

CIPO record

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Abstract From the Canadian patent

In a photographic copy process the copy master is scanned in intervals, by a source of measuring light. The measuring light is spectrally split, detected and converted into electrical measuring signals. The n spectral measuring signals are converted into n spectral density values compared with, neutral densities and n spectral density differences formed. In a data compression the n spectral density differences are converted by an orthogonal transformation to m < n transformation coefficients. The transformation coefficients are analyzed in a color and density correction routine and deviations computed. From the deviations the copy light quantities and exposure corrections adjusted to the …

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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 September 6, 1991 and granted March 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 6, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 6, 2013.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 6, 1991
GrantedMarch 6, 2001
Term endedSeptember 6, 2011
Patent numberCA 2050807 C
Classification (IPC)H04N1/46 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedSep 6, 1991Patent grantedMarch 6, 2001Term endedSep 6, 2011

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