Viewing Heilmeier displays

For monochrome applications, one can either put a monochrome color filter inside the cell or use monochromatic back-lighting. For Heilmeier displays, there is another way to get a monochrome display by using monochromatic pleochroic dyes [26]. For full-color display, color filters must be used. Heilmeier displays exhibit better color performance than TN displays, as the chroma-ticity of the pixels does not change much at large viewing angles. 

Table 2. Contrast ratio and percent transmission of Heilmeier, dye doped TN, and TN displays versus viewing angle [16].

Recently, Ong [126] proposed a Heilmei-er display having two asymmetric cells. This display has a high contrast and wide viewing angles, but low transmission. One can also use two separate Heilmeier cells with different dyes to make a composite cell, and by controlling voltage differently a set of colors can be obtained. Two cells with different dyes and one polarizer, can also be used. 

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