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Expired European patentEurope

Optical data storage system with multiple write-once phase-change recording layers

EP 0835508 B1 · Applicant: International Business Machines 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 March 8, 1996 and granted December 1, 1999. A European patent lasts at most 20 years from filing, so its term ended March 8, 2016.
  • 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 September 8, 2021.
  • 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.
FiledMarch 8, 1996
PublishedApril 15, 1998
GrantedDecember 1, 1999
Term endedMarch 8, 2016
Application numberEP 96904970
Classification (CPC)G11B7/24038 +2 more

Timeline

Timeline From EPO dates

1997199920012003200520072009201120132015Application filedMarch 8, 1996PublishedApril 15, 1998Patent grantedDec 1, 1999Term endedMarch 8, 2016

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