LCD - Graphical

A liquid-crystal display (LCD) is a flat-panel display or another electronically modulated optical device that uses the light-modulating properties of liquid crystals. Liquid crystals do not emit light directly, instead using a backlight or reflector to produce images in colour or monochrome. LCDs are available to display arbitrary or fixed images with low information content, which can be displayed or hidden, such as pre-set words, digits, and 7-segment displays, as in a digital clock. They use the same basic technology, except that arbitrary images are made up of a large number of small pixels, while other displays have larger elements.

TFT displays comprise thousands or millions of tiny transistors, each of which controls a single pixel. This construction allows the screen to show fast moving images, as the pictures can be redrawn rapidly. They provide high brightness with good contrast, backlighting and excellent colour quality. Most designs can also be provided with touch screen capability. TFT modules are also thin and lightweight, enabling them to be used for a variety of projects.

Liquid crystals are substances that exhibit properties of both solids and liquids; they are an intermediate phase of matter. Liquid crystals can be classified into three different groups, nematic, smectic, and cholesteric depending on the level of order in their molecular structure. Liquid crystals in the nematic group are most commonly used in LCD production because of their physical properties and wide temperature range. In the nematic phase, liquid crystal molecules are oriented on average along with a particular direction. By applying an electric or magnetic field, the orientation of the molecules can be manipulated in a predictable manner; this mechanism provides the basis for LCDs. Simple LCDs consist of a liquid crystal cell, conductive electrodes and a set of polarizing lenses

There are a number of different technologies available to provide the touch function, such as SAW (surface acoustic wave), capacitive, infra red or analogue resistive. The input adapter for TFT modules can be along with built-in VGA, DVI and RGB compatibility to ensure simple plug and play operation. The latest technology uses Transflective Mode which uses mirror coating and colour filters to produce a unit which is sunlight readable

TFT or the thin-film transistor LCDs have been around the longest, and are used in many products. They are available in a wide range of sizes, which make them the preferred type of module for smartphone manufacturers who want to give their customers wider screens.