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Expired European patentEurope

Multiplex magnetic recording and reproduction system

EP 0117455 B1 · Applicant: HITACHI, LTD.

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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.

Why it's free to use

  • Filed February 2, 1984 and granted June 11, 1986. A European patent lasts at most 20 years from filing, so its term ended February 2, 2004.
  • 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 August 2, 2009.
  • 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.
FiledFebruary 2, 1984
PublishedSeptember 5, 1984
GrantedJune 11, 1986
Term endedFebruary 2, 2004
Application numberEP 84101057
Classification (CPC)G11B20/22 +2 more

Timeline

Timeline From EPO dates

1985198719891991199319951997199920012003Application filedFeb 2, 1984PublishedSep 5, 1984Patent grantedJune 11, 1986Term endedFeb 2, 2004

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