JPS54115143A - Reflection type liquid crystal display device - Google Patents

Abstract

PURPOSE: To form a display device of high contrast and low driving voltage by constituting its liquid crystal layer with liquid crystals of chiral type dichromatic base in the reflection type liquid crystal display device of guest-hose type in which a phase plate is provided between the liquid crystal layer and reflecting plate.

CONSTITUTION: Liquid crystal 7 having chirality and dichromatic dyes 8 are contained between the upper and lower substrates 1, 2 respectively provided with transparent electrodes 3, 4 and orientation treated layers 5, 6. A 1/4 wavelength phase plate 10 is then so installed that its optical axis becomes 45° to the orientation direction of the liquid crystal 7 and dichromatic dyes 8 of the lower substrate 2. Where no electric field is applied between the electrodes 3, 4, the incident light 14 having no polarization passes through the liquid crystal layer and becomes elliptically polarized light like 15. Next, it passes through the phase plate 10, diffusion reflecting plate 9 and phase plate 10 to become the elliptically polarized light differing by 90° in the axis of polarization from 15 and therefore the light 26 again transmitted through the liquid crystal layer has received sufficient absorption. On the other hand, where an electric field is applied between the electrodes 3, 4, the liquid crystal 7 and dyes 8 array perpendicularly to the plane of the substrates and therefore the incident light is hardly absorbed.

COPYRIGHT: (C)1979,JPO&Japio