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Expired European patentEurope

Method of coloring photochromic glasses

EP 0452640 B1 · Applicant: CORNING INCORPORATED

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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 February 28, 1991 and granted December 7, 1994. A European patent lasts at most 20 years from filing, so its term ended February 28, 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 August 28, 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.
FiledFebruary 28, 1991
PublishedOctober 23, 1991
GrantedDecember 7, 1994
Term endedFebruary 28, 2011
Application numberEP 91102896
Classification (CPC)C03C4/06

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedFeb 28, 1991PublishedOct 23, 1991Patent grantedDec 7, 1994Term endedFeb 28, 2011

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.