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Expired European patentEurope

Electrochromic display device with improved erasing characteristic

EP 0044392 B1 · Applicant: AMERICAN CYANAMID COMPANY

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Overview

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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 June 1, 1981 and granted August 1, 1984. A European patent lasts at most 20 years from filing, so its term ended June 1, 2001.
  • 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 December 1, 2006.
  • 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.
FiledJune 1, 1981
PublishedJanuary 27, 1982
GrantedAugust 1, 1984
Term endedJune 1, 2001
Application numberEP 81104174
Classification (CPC)G02F1/1524

Timeline

Timeline From EPO dates

1982198419861988199019921994199619982000Application filedJune 1, 1981PublishedJan 27, 1982Patent grantedAug 1, 1984Term endedJune 1, 2001

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.