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Expired Canadian patentCanada

Symmetric optical device

CA 1298388 C · Owner: Hinton, Harvard Scott · Inventors: Hinton, Harvard Scott; Miller, David Andrew Barclay; Lentine, Anothony Lodovico

CIPO record

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

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Abstract From the Canadian patent

Abstract, An optically bistable device 100 is disclosed having first and second semiconductor multiple quantum well regions 101 and 102 with complementary high and low absorption levels for emitting first and second output light beams 162 and 163 having complementary low and high power levels. The optical device comprises first and second photodetectors 103 and 104 having respective quantum well regions 101 and 102. The photodetectors are responsive to first and second light beams 160 and 161 for electrically controlling the optical absorption of each of the two quantum well regions. The state of the device is determined by the transmission level of light beam 161 passing through multiple …

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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 March 31, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 31, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 28, 1988
GrantedMarch 31, 1992
Term endedMarch 31, 2009
Patent numberCA 1298388 C
Classification (IPC)G02F3/02 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedMarch 28, 1988Patent grantedMarch 31, 1992Term endedMarch 31, 2009

Sources & verification

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