What is FLCD?
| Ferroelectric Liquid Crystal Display |
|
Normal liquid crystals remain transparent unless a voltage is placed across them. While the voltage is applied, the portion of the display under its influence remains opaque. The speed at which the liquid crystal can be switched on and off is relatively slow, and the need to control each element (pixel) of a display makes it difficult to manufacture computer and TV screens. In 1992 Thorn EMI announced a new type of LCD called FLCD. This switches more quickly and, in addition, has the ability for each pixel switched on or off to remain so without the need for the switching voltage to be constantly applied. A greatly increased battery life for portable equipment will result. Research is continuing to produce FLCD colour screens. FLCDs hold much in promise when it comes to commercialized applications, but one major disadvantage is the manufacturing problem due to a very small cell spacing, about 1.5 microns +/- 0.05 microns, which is a very severe tolerance. Monochrome and full color 15-inch diagonal ferroelectric LCDs are now under production and sizes up to 17 or even 19 inch diagonals may soon be possible to manufacture for office applications in the near future. The sensitivity to shock and vibration is believed to be solved and the contrast ratio is also improved as the limitation of defects increase. Sony is currently using SiO evaporation for alignment layers to improve uniformity and contrast ratio. They are also in lead when it comes to gray scale techniques to address the video requirement. The future for ferroelectric LCDs is still uncertain, but if a higher contrast and wider viewing angle is achieved, they may actually compete with active matrix LCDs. What is the response time for the FLCD? The FLCD has the advantage that the on and off switching times are the same, unlike other displays. The response time is 70µsec at normal projector working temperatures. |
Beginner's Help
BUG Club Home
