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Expired European patentEurope

Differential amplifying circuit

EP 0467655 B1 · Applicant: NEC CORPORATION

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Overview

The published document from the EPO: abstract, claims, description and drawings. Open it full size

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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 16, 1991 and granted June 14, 1995. A European patent lasts at most 20 years from filing, so its term ended July 16, 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 16, 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 16, 1991
PublishedJanuary 22, 1992
GrantedJune 14, 1995
Term endedJuly 16, 2011
Application numberEP 91306470
Classification (CPC)H03F3/45071 +1 more

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedJuly 16, 1991PublishedJan 22, 1992Patent grantedJune 14, 1995Term endedJuly 16, 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

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.