Patent · US Expired

Transmissive and reflective liquid crystal display

US4315258A · kind A · utility

89Cited by
1References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 15, 1980
Grant dateFeb 9, 1982
Priority date
Expiry dateFeb 15, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F2203/09
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A visual display has an increased readout capability due to its operation the transflective mode. A source of ambient light and light for radiation through the display from the backside together assure the increased readout capability. Heretofore, ambient light would degrade or washout a display making it nearly impossible for monitoring personnel to decipher alphanumeric or pictoral displays due to the decreased contrast. A pair of linear polarizers sandwich a twisted nematic liquid crystal and have their polarization axes either parallel or mutually orthogonally disposed so that the crystal will present bright or dark areas in response to applied potentials. Because a partially transmitting mirror is interposed between the sandwiched liquid crystal and the radiating light source, the ambient light augments the radiated light to enhance the visual display.

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