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Expired Canadian patentCanada

Phase retarder and liquid crystal display using the same

CA 1312759 C · Owner: Kikui, Hitoshi · Inventors: Nakamura, Kimishige; Sakakura, Kazuaki; Higashi, Koji

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Abstract From the Canadian patent

A phase retarder obtained by uniaxially stretching a thermoplastic resin film, whose retardation value ranges from 30 to 1200 nm and whose color difference .DELTA.E* is not more than 30 as defined with the phase retarder being set between crossed polarizers in such a manner that the optical axis thereof makes an angle of 45° with respect to the planes of polarization of the polarizers, and a liquid crystal display using the phase retarder are disclosed. The phase retarder has a fixed optical axis, a retardation value suited for new optical uses including liquid crystal displays and, freedom from optical color unevenness. The liquid crystal display using the phase retarder exhibits markedly …

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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

  • Granted January 19, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 19, 2010.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 29, 1988
GrantedJanuary 19, 1993
Term endedJanuary 19, 2010
Patent numberCA 1312759 C
Classification (IPC)G02B27/28 +2 more

Timeline

Timeline From CIPO dates

19891992199519982001200420072010Application filedJune 29, 1988Patent grantedJan 19, 1993Term endedJan 19, 2010

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