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Expired European patentEurope

Tracking error detection

EP 0458531 B1 · Applicant: SONY 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.

Why it's free to use

  • Filed May 16, 1991 and granted February 28, 1996. A European patent lasts at most 20 years from filing, so its term ended May 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 November 16, 2016.
  • 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 16, 1991
PublishedNovember 27, 1991
GrantedFebruary 28, 1996
Term endedMay 16, 2011
Application numberEP 91304429
Classification (CPC)G11B15/4678

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedMay 16, 1991PublishedNov 27, 1991Patent grantedFeb 28, 1996Term endedMay 16, 2011

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