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Expired Canadian patentCanada

Projection-type liquid crystal display device

CA 2201689 C · Owner: Tamano, Kouhei · Inventors: Sugiura, Hiroaki; Ishida, Kozo; Tamano, Kouhei

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 projection-type liquid crystal display device having a light source for emitting a luminous flux; a liquid crystal light valve for modulating the luminous flux emitted by the light source means; a liquid crystal drive circuit for applying the common voltage to the common electrode and the video signal to the source electrode; a projection lens for projecting the luminous flux modulated by the liquid crystal light valve onto a screen; a liquid crystal temperature detector for detecting temperature in the vicinity of the liquid crystal light valve; and a controller. The controller controls the common voltage and/or the source voltage on the basis of values detected by the liquid crystal …

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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 April 3, 1997 and granted November 28, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 3, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 3, 2019.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 3, 1997
GrantedNovember 28, 2000
Term endedApril 3, 2017
Patent numberCA 2201689 C
Classification (IPC)G02F1/13 +2 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedApril 3, 1997Patent grantedNov 28, 2000Term endedApril 3, 2017

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