This invention relates to reflective cholesteric displays without using Bragg reflection. The
helical pitch of the cholesteric liquid crystals may or may not be tuned in a visible
wavelength, but its Bragg reflection will never be displayed. An elliptical
polarizer with properly designed retardation and lamination positioned at the front of the display will be able to eliminate the Bragg reflection over a large
viewing cone. The function of the display
cell structure is merely a light
shutter to switch the incident light ON and OFF. In the black-and-white display mode, the white state is achieved from the
metal reflection in the cholesteric planar texture area; and the black state is obtained by cholesteric's
depolarization effect and
polarizer's
filtration effect in the cholesteric focal conic texture area. In the
full color mode, the
full color state is created by the
metal reflector and the micro-color filter in the cholesteric planar texture area; and the black state is realized in the cholesteric focal conic texture area. The reflective cholesteric display, remaining its long-term
bistability but not applying the narrow-band Bragg reflection, initiates novel displays with a neutral wide-band reflection.