Patent · US Expired

Liquid crystal electrical fault indicators

US5066104A · kind A · utility

7Cited by
14References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 25, 1988
Grant dateNov 19, 1991
Priority date
Expiry dateMar 25, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/1313
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An electrical apparatus having a liquid crystal fault indicator, comprising: an electrical component subject to electrical fault; a smectic liquid crystal display having an indicating element having a first and a second visual state, said indicating element being capable of transitioning from the first to the second visual state upon the application of an electric field sufficient to realign the smectic liquid crystal material contained therein and remaining in the second visual state after the removal of the electric field and further being capable of transitioning from the second to the first visual state upon heating to at least a delatching temperature Td sufficient to destroy the electric field induced alignment of the smectic liquid crystals; and fault signal means for providing, upon the occurrence of a fault, a prescribed input sufficient to cause said indicating element to transition from a visual state indicative of an unfaulted condition to a visual state indicative of a faulted condition.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.