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Expired European patentEurope

Optical time domain reflectometry

EP 0478654 B1 · Applicant: BRITISH TELECOMMUNICATIONS public limited company

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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 June 22, 1990 and granted November 10, 1993. A European patent lasts at most 20 years from filing, so its term ended June 22, 2010.
  • 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 December 22, 2015.
  • 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.
FiledJune 22, 1990
PublishedApril 8, 1992
GrantedNovember 10, 1993
Term endedJune 22, 2010
Application numberEP 90909768
Classification (CPC)G01M11/319

Timeline

Timeline From EPO dates

1991199319951997199920012003200520072009Application filedJune 22, 1990PublishedApril 8, 1992Patent grantedNov 10, 1993Term endedJune 22, 2010

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

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.