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Expired European patentEurope

Method of determining the refractive index profile of an optical fibre

EP 0029195 B1 · Applicant: CSELT Centro Studi e Laboratori Telecomunicazioni S.p.A.

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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 November 10, 1980 and granted February 8, 1984. A European patent lasts at most 20 years from filing, so its term ended November 10, 2000.
  • 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 May 10, 2006.
  • 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.
FiledNovember 10, 1980
PublishedMay 27, 1981
GrantedFebruary 8, 1984
Term endedNovember 10, 2000
Application numberEP 80106913
Classification (CPC)G01N21/412

Timeline

Timeline From EPO dates

1981198319851987198919911993199519971999Application filedNov 10, 1980PublishedMay 27, 1981Patent grantedFeb 8, 1984Term endedNov 10, 2000

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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