Expired European patentEurope
Liquid crystal optical devices
EP 0249311 B1 · Applicant: BRITISH TELECOMMUNICATIONS public limited company
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 31, 1987 and granted December 29, 1993. A European patent lasts at most 20 years from filing, so its term ended March 31, 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 October 1, 2012.
- 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 31, 1987
PublishedDecember 16, 1987
GrantedDecember 29, 1993
Term endedMarch 31, 2007
Application numberEP 87302816
Classification (CPC)G02F1/292 +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.