How does the backlight of a LCD watch works?

Question

What kind of component used in it? is it LED?

Answer 1

Some watches use what is called an EL (electro-luminescent) panel. It is a very thin piece of plastic behind the LCD glass. When high voltage is applied across the plastic, special chemicals emit light.

This technology commonly goes under the name indigo, and had a bluish, green quality to the light. The light is very even and makes it easy to read.

Answer 2

All LCD screens need a back light. In some cases it can be a low voltage lamp (as in the case of a watch), while in others it may require a higher voltage one (as in the case of motorcycle systems that use a 14 volt lamp). Some watches do use an LED and others use a so called "grain of wheat" low voltage lamp. They are quite small and draw very little current.