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Expired Canadian patentCanada

Image display apparatus

CA 2032680 C · Owner: Minoura, Nobuo · Inventors: Mitsutake, Hideaki; Minoura, Nobuo

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

An image display apparatus has a radiation source, generator for generating an image by modulating a polarized light beam and directing device for directing a light beam from the radiation source toward the generator. The directing device has a conversion optical system for converting the beam from the radiation source into the polarized light beam. The conversion optical system has a polarizing beam splitter for splitting the beam from the radiation source into a first and second beams. In the conversion optical system a 1/4 wavelength, plate and a mirror are arranged so that the plane of polarization of the first beam is rotated to generate a third beam with the plane of polarization same …

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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 December 19, 1990 and granted December 20, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 19, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 19, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 19, 1990
GrantedDecember 20, 1994
Term endedDecember 19, 2010
Patent numberCA 2032680 C
Classification (IPC)G02B26/10 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedDec 19, 1990Patent grantedDec 20, 1994Term endedDec 19, 2010

Sources & verification

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