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Expired Canadian patentCanada

Broadband rugate filter

CA 2122929 C · Owner: Hughes Aircraft Company · Inventors: Rahmlow, Thomas D.; Turner, Aaron

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 broadband rugate filter (10) includes an optical substrate (12) having first and second surfaces (14, 16) and a layer (18) of optical material deposited on one of the surfaces (14, 16). The layer (18) has an index of refraction versus thickness profile having a frequency that continuously changes in a single direction

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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 5, 1994 and granted March 25, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 5, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 5, 2016.
  • 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 5, 1994
GrantedMarch 25, 1997
Term endedMay 5, 2014
Patent numberCA 2122929 C
Classification (IPC)G02B5/26 +1 more

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedMay 5, 1994Patent grantedMarch 25, 1997Term endedMay 5, 2014

Sources & verification

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