Optimization of “Guest-Host” Liquid Crystal Display

Abstract

Using MOUSE-LCD software we analyze, how the parameters of the “guest-host” cell effects such basic characteristics of LCDs as the contrast, brightness and magnitude of the viewing angles. The basic construction of “guest-host” LCD includes one input polarizer and reveals a negative contrast. We showed, that to increase the average contrast, transmission and viewing angles of “guest-host” LCDs we have to use the LC cells with the twist angle of 90°, while the thickness of the LC layer should be sufficiently high. The concentration of the dye must be optimized for the applied values of LC cell thickness and twist angle. The higher values of LC optical anisotropy Δn results in the increase of the display contrast in our case, contrary to the non-polaroid variant of “guest-host” LCDs.

One-polarizer construction of a transmissive “guest-host” LCD with a phase retardation plate was also analyzed. The application of a phase compensator in GH-LCDs allows to use thin LC cells with a high concentration of dichroic dye to get a maximum contrast and transmission for minimum response times. Our calculations may be helpful for the production of the new efficient “guest-host” LCD configurations

Key Words:

• “guest-host” effect
• LCD
• contrast
• brightness
• dichroic dye