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Expired European patentEurope

Variable phase stop for use in interferometers

EP 0303630 B1 · Applicant: Hughes Aircraft Company

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Overview

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

Read the whole patent

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 December 14, 1987 and granted August 4, 1993. A European patent lasts at most 20 years from filing, so its term ended December 14, 2007.
  • 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 June 14, 2013.
  • 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.
FiledDecember 14, 1987
PublishedFebruary 22, 1989
GrantedAugust 4, 1993
Term endedDecember 14, 2007
Application numberEP 88900737
Classification (CPC)G02F1/1313 +2 more

Timeline

Timeline From EPO dates

1988199019921994199619982000200220042006Application filedDec 14, 1987PublishedFeb 22, 1989Patent grantedAug 4, 1993Term endedDec 14, 2007

Sources & verification