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Expired European patentEurope

Method of detecting angle of optical rotation in solution having time-dependent concentration, detection apparatus therefor, and detector cell therefor

EP 0468487 B1 · Applicant: SHOWA DENKO KABUSHIKI KAISHA

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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 July 24, 1991 and granted December 21, 1994. A European patent lasts at most 20 years from filing, so its term ended July 24, 2011.
  • 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 January 24, 2017.
  • 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.
FiledJuly 24, 1991
PublishedJanuary 29, 1992
GrantedDecember 21, 1994
Term endedJuly 24, 2011
Application numberEP 91112449
Classification (CPC)G01J4/04 +1 more

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedJuly 24, 1991PublishedJan 29, 1992Patent grantedDec 21, 1994Term endedJuly 24, 2011

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

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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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