Expired European patentEurope
Furnace for formation of black oxide film on the surface of thin metal sheet and method for formation of black oxide film on the surface of shadow mask material by use of said furnace
EP 0284233 B1 · Applicant: KABUSHIKI KAISHA TOSHIBA
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 March 7, 1988 and granted July 1, 1992. A European patent lasts at most 20 years from filing, so its term ended March 7, 2008.
- 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 7, 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.
FiledMarch 7, 1988
PublishedSeptember 28, 1988
GrantedJuly 1, 1992
Term endedMarch 7, 2008
Application numberEP 88301977
Classification (CPC)C21D9/0062 +2 more
Timeline
Timeline From EPO dates
Sources & verification
Official EPO records
Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.