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Expired Canadian patentCanada

Improvements in or relating to the addressing of liquid crystal displays

CA 2222064 C · Owner: Surguy, Paul William Herbert · Inventors: Surguy, Paul William Herbert

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A liquid crystal device of the kind in which individually addressable regions are settable to different optical states in response to drive waveforms is described. The waveforms are used to cause the material in different regions to remain set in its existing optical state or to change to another state in dependence upon data to be input to the device, and they are pulse-like in nature and of predetermined amplitude and duration. The operating speed of the device in response to said waveform is improved by causing the profile of the waveforms to depart from the usual squared profile. In one example the waveforms are caused to have substantially triangular leading and/or trailing edges and …

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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 May 13, 1996 and granted April 9, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 13, 2016.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 13, 2018.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 13, 1996
GrantedApril 9, 2002
Term endedMay 13, 2016
Patent numberCA 2222064 C
Classification (IPC)G09G3/36

Timeline

Timeline From CIPO dates

1997199920012003200520072009201120132015Application filedMay 13, 1996Patent grantedApril 9, 2002Term endedMay 13, 2016

Sources & verification

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