Multicolor Switching Properties in Fluorescent Liquid Crystal Displays

Multicolor fluorescent liquid crystal displays (LCDs) are proposed. The twisted nematic (TN) cell containing a dichroic fluorescent dye is utilized as a UV shutter, a polarization switch and an active emitter. We describe two fluorescent LCD modes of different stacking order of the fluorescent TN cell, alternative fluorescent layer and a sheet polarizer. The fluorescence color can continuously be changed by applying a voltage across the TN cell and color variations between green and blue, red and green, and red and blue are demonstrated in both modes. The brightness is considerably improved by applying the polarized light emitting phenomenon from the LC cell to the fluorescent LCD, which makes the use of nonpolarized excitation UV light possible.