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Expired European patentEurope

Semiconductor laser light modulation and demodulation system

EP 0172775 B1 · Applicant: HOKKAIDO UNIVERSITY

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Overview

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Filed August 21, 1985 and granted May 22, 1991. A European patent lasts at most 20 years from filing, so its term ended August 21, 2005.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by February 21, 2011.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledAugust 21, 1985
PublishedFebruary 26, 1986
GrantedMay 22, 1991
Term endedAugust 21, 2005
Application numberEP 85401664
Classification (CPC)H04B10/50 +2 more

Timeline

Timeline From EPO dates

1986198819901992199419961998200020022004Application filedAug 21, 1985PublishedFeb 26, 1986Patent grantedMay 22, 1991Term endedAug 21, 2005

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

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