In the planar state the cell reflects incident rays due to selective reflection from the texture, and appears bright. In the focal conic state the incident rays are transmitted and typically absorbed by a non-reflective coating on the rear of the cell. In a strong electric field a homeotropic texture that is transparent to the light appears and light is once again absorbed by the non reflective coating on the back of the cell.

PSCT type devices require no polarizers, have excellent brightness capabilities and can provide colored displays. ^{[18] [2]} Contrast ratios around 6 ^[18] and reflectivity around 30% ^[18] have been reported. Stacked layers of RGB can provide colored displays (see figure 20 above). Selective reflection of the cholesteric structure provides high reflectivity for the selected spectrum range ~50%, sharp threshold and bistability. The problem with this technology however is a high drive voltage and relatively slow writing speed for moving images.

Minolta in SID97 ^[18] proposed adding red dye to the red composite in a RGB layer structure (see above fig 10). They claim this improves the reflective properties, especially the color purity.

In IDW97 scientists from the Changchun Inst. Of Physics and Chinese Academy of Science ^[2] introduced a new method of achieving reflective multicolor bistable LCD.

The method they used was to fix the reflected color in the display was to change the temperature of the cure (thermochroic effect) rather than the intensity of the UV light ,which is a method usually used. Utilizing this and a photolithographic process (see above fig 21) different colors were pixelized to form a reflective multicolor display. This display has an " advantage over the ones created using UV cure in that the pattern of the pixel does not bleach over time ". Compared to a three layer device it has a lower weight also. Numbers for reflectivity and CR were not mentioned.

Cholesteric LCDs such as the ones made by Kent Displays are bistable (without polymer) have a " wide viewing angle and offer unlimited multiplexing ". The absence of polarizers allows a good brightness. In the planar state the display reflects a narrow bandwidth of light, and in the focal conic state is weakly scattering. Colors are produced by stacking Ch-LCDs, four or eight colors can be produced by stacking blue and yellow or blue green and red, see figure 22.

Parallax is claimed not be a problem upto 50 degrees. The technology however suffers from voltage and CR issues.

Toshiba in SID 97 introduced a high reflective LCD with double cholesteric LC layers ^[13]. One of the layers had a right handed twist and the other a left handed twist see figure 23.

Ideally this would provide double the reflectance of a single cholesteric as both right and left polarized light would be reflected. However they only achieved a 1.5 times performance. This can be improved according to them by optimizing the middle separator to pass more light through it.

In IDW 97 Toshiba also introduced a monochrome high brightness reflective TFT-LCD ^[4] using cholesteric texture, see figure 24.

The device reportedly shows a " contrast ratio of 20 with a reflectance of 30% and a CR of > 10 with a reflectance of 60% ".

In SID 98 Minolta ^[32] introduced a reflective color display using stacked cholesteric LCs. The display had a " high luminance, 512 color capability, and bistability ".

They introduced a new driving scheme called the focal conic reset FCR scheme (see fig 25). This driving method " achieves 512 color capability for stacked-type cholesteric LCDs ". Minolta also proposed a new panel fabrication method using heat press adhesive process for film substrate LCDs. This method allows " easy low cost production of large size film LCDs ".