Liquid Crystal Reflection Cell with Improved Response Times

Abstract

In recent papers the authors described a liquid crystal (LC) device, operated in the transmission mode, that had response times of the order of 0.2-0.4 msec and contrasts of ~6%. These response times are considerably faster than the 20-50 msec normally associated with cells using the twisted nematic configuration. The improvement in response time results from (1) the addition of a small amount of a cholesteric to a binary nematic, and (2) operation of the cell with the signal voltage superimposed on a square-wave pedestal voltage whose polarity is reversed at a 20-Hz rate. With an aim toward incorporating these features into a light valve of the type described by Beard et al., which uses a photoconductor-LC sandwich configuration, we have carried out experiments similar to those described earlier but on a cell in the reflection mode.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1980
Accession Number
ADA093912

Entities

People

  • Herbert Hacker
  • I. Lefkowitz
  • R. Lontz

Organizations

  • Duke University

Tags

Communities of Interest

  • Advanced Electronics
  • Cyber

DTIC Thesaurus Topics

  • Advanced Materials
  • Classification
  • Contrast
  • Crystals
  • Data Processing
  • Electrical Conductivity
  • Films
  • Liquid Crystals
  • Military Research
  • North Carolina
  • Optics
  • Physics
  • Polarity
  • Security
  • Square Waves
  • Universities
  • Waves

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Microwave Engineering.
  • Vision Science/Vision Psychology/Cognitive Neuroscience.