| 摘要 |
<p>A liquid crystal display comprises a body of a nematic liquid crystal host material (1) which contains a pleochroic fluorescent dye and which is supertwisted. Parameters of the display are selected such that the display has a transmission wavelength spectrum which encompasses the emission spectrum of the fluorescent dye. In a backlit mode, the display operates in transmission and the light from an electroluminescent panel (11) excites the fluorescent dye in the liquid crystal. In high ambient light levels, the display operates in a reflective mode and the fluorescence is excited by ambient blue or ultraviolet light. The absorption and the fluorescence of the dye are anisotropic, so that switched segments appear dark. In unswitched regions of the display, however, the fluorescence is excited and gives a bright background to the display. Hence, the effect of the fluorophor is to improve the brightness of the display.</p> |
