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Expired European patentEurope

Amplifying apparatus with a differential amplifier stage

EP 0400643 B1 · Applicant: KABUSHIKI KAISHA TOSHIBA

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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 31, 1990 and granted January 12, 1994. A European patent lasts at most 20 years from filing, so its term ended May 31, 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 1, 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.
FiledMay 31, 1990
PublishedDecember 5, 1990
GrantedJanuary 12, 1994
Term endedMay 31, 2010
Application numberEP 90110362
Classification (CPC)H03F1/305

Timeline

Timeline From EPO dates

1991199319951997199920012003200520072009Application filedMay 31, 1990PublishedDec 5, 1990Patent grantedJan 12, 1994Term endedMay 31, 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.