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Expired Canadian patentCanada

Polarizing element and image display apparatus having the polarizing element

CA 2064669 C · Owner: Mitsutake, Hideaki · Inventors: Kimura, Kazumi; Mitsutake, Hideaki

CIPO record

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Abstract From the Canadian patent

A polarizing device has first and second half-wave plates and a separating device for separating incident light thereon into first and second linearly polarized lights whose polarized directions are orthogonal to each other. The direction of polarization of the first linearly polarized light is caused to rotate by the first half-wave plate. The direction of polarization of the second linearly polarized light is caused to rotate by the second half-wave plate. The first and second half-wave plates are disposed such that the optical axes of the first and second half-wave plates defines an angle of 45°.

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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 1, 1992 and granted July 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 1, 2012.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 1, 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.
FiledApril 1, 1992
GrantedJuly 27, 1999
Term endedApril 1, 2012
Patent numberCA 2064669 C
Classification (IPC)G02B27/28 +2 more

Timeline

Timeline From CIPO dates

1993199519971999200120032005200720092011Application filedApril 1, 1992Patent grantedJuly 27, 1999Term endedApril 1, 2012

Sources & verification

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