Reflective liquid crystal display and transmissive dye-doped liquid crystal display

A reflective liquid crystal display, comprising:

• a twisted nematic liquid crystal (LC) cell having an input plate, an output plate and 90.degree. twist LC molecules having a d.DELTA.n/.lambda. in the approximate range of 0.2-0.8, where d is the thickness of said twisted nematic LC cell in microns, .DELTA.n is the difference between the ordinary and extraordinary refractive indices of the LC molecules, and .lambda. is the wavelength of incident light in microns, the LC molecules having directors, the directors of the LC molecules on the side of said input plate being oriented at a substantial non-zero angle to the directors of the LC molecules on the side of said output plate;
• electrodes positioned on said input plate and output plate respectively to establish an electric field through said twisted nematic LC cell to modulate optical transmissivity through mixed polarization rotation and birefringence effects;
• and
• an optical polarizer positioned to polarize input light to said twisted nematic LC cell, the directors of said LC molecules adjacent said input side being oriented at an angle .beta. to the polarization orientation of light from said polarizer, where .beta. is substantially greater than 0.degree. and substantially less than 90.degree.
• wherein .beta. is selected in combination with d.DELTA.n to obtain mixed polarization rotation and birefringence effects.