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Expired European patentEurope

Optical waveplate, method of manufacturing the same, and waveguide device using the same

EP 0623830 B1 · Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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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 May 3, 1994 and granted August 18, 1999. A European patent lasts at most 20 years from filing, so its term ended May 3, 2014.
  • 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 November 3, 2019.
  • 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.
FiledMay 3, 1994
PublishedNovember 9, 1994
GrantedAugust 18, 1999
Term endedMay 3, 2014
Application numberEP 94106902
Classification (CPC)G02B5/3083 +2 more

Timeline

Timeline From EPO dates

1995199719992001200320052007200920112013Application filedMay 3, 1994PublishedNov 9, 1994Patent grantedAug 18, 1999Term endedMay 3, 2014

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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