Liquid crystal displays have been widely used in our
daily life. We can see many applications in portable and household
electronic products. Because of the visual effect and the fashionable
reasons, color display should be more popular than
monochromatic display. Color STN-LCDs can meet our need for colorful picture
display. Although the electro-optical properties of color
STN-LCDs, such as contrast, viewing angle and response
time, are not as good as that of color TFT-LCDs, they
could still be a nice choice for those who care about
the cost but do not concern about response time in video
The structure of color STN-LCDs, including color filter,
retardation film and STN-LCD panel, is showing in Fig. 1.
A gray scale
scheme is applied to control the transmittance of R, G,
B pixels on color filter. By the different proportion of
R, G, B elements, we can get many kinds of color.
Additionally, we can get higher contrast and wider
viewing angle on the display due to optical compensation
properties of retardation film.
For handheld devices, the power-consumption is a very
important issue. So several new technologies have developed for low
power-consumption application. Because the backlight's power-consumption is the large
part for Color STN Display, display without backlight is
the best technology for low power-consumption. These new technology, named Reflective and Transflective
Color STN Display, are more and more popular because of
their low power-consumption. The structure of Reflective and Transflective Color STN
Panel is shown as picture illustrated:
with Transmissive Color STN, shown as above picture, the
Al reflector is the new component in Reflective and
Transflective LCD Panel.