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Expired Canadian patentCanada

Optical repeater having phase inversion circuit

CA 2027051 C · Owner: Fujitsu Limited · Inventors: Fujiwara, Haruo; Kitamura, Mitsuo

CIPO record

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Abstract From the Canadian patent

An optical repeater includes a first converter converting an optical input signal into an electrical signal, an equalizing amplifier which amplifies the electrical signal and which outputs an amplified electrical signal, and a timing extraction circuit which extracts a timing signal from the amplified electrical signal. Also the optical repeater includes a phase inversion circuit which receives the amplified electrical signal in synchronism with the timing signal and which outputs a phase-inverted signal in synchronism with the timing signal. The phase-inverted signal has a phase opposite to a phase of the amplified electrical signal. Further the, optical repeater includes a second …

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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 October 5, 1990 and granted October 5, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 5, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 5, 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.
FiledOctober 5, 1990
GrantedOctober 5, 1993
Term endedOctober 5, 2010
Patent numberCA 2027051 C
Classification (IPC)H04B10/16

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedOct 5, 1990Patent grantedOct 5, 1993Term endedOct 5, 2010

Sources & verification

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