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Expired European patentEurope

Optical light waveguide switching element, and switching matrix composed of a multitude of such an element

EP 0274796 B1 · Applicant: ALCATEL ALSTHOM RECHERCHE Société Anonyme

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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 December 16, 1987 and granted May 19, 1993. A European patent lasts at most 20 years from filing, so its term ended December 16, 2007.
  • 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 June 16, 2013.
  • 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.
FiledDecember 16, 1987
PublishedJuly 20, 1988
GrantedMay 19, 1993
Term endedDecember 16, 2007
Application numberEP 87202544
Classification (CPC)G02F1/3133

Timeline

Timeline From EPO dates

1988199019921994199619982000200220042006Application filedDec 16, 1987PublishedJuly 20, 1988Patent grantedMay 19, 1993Term endedDec 16, 2007

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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