| | | | Liquid Crystal Display. The display technology used in laptops/notebooks and other small devices such as watches and calculators. LCD panels use far less power than traditional CRT (Cathode Ray Tube), LED (Light Emitting Diode) and Gas-Plasma displays, meaning that they can be run on battery power rather than the mains supply. This fact, along with the falling cost of producing them, has been responsible for the rise of portable computing devices. The main reason for their lower power consumption is that rather than emitting light, LCDs work on the principle of blocking light by manipulating the alignment of a solution of rod-shaped crystals. The basic construction on an LCD is a layer of liquid crystals, sandwiched between two transparent electrodes and two polarising filters. By passing current through the electrodes, the crystals of a specific portion of the display can be made to align, which blocks light from the light source behind the display from passing through, creating a visible image. The display is comprised of number of distinct cells called Pixels (derived from "picture element"). Each pixel is a logical unit of area of the display defined by it's resolution. This is not to be confused with "Dot Pitch" which denotes the physical dots on the display - as the resolution is altered the number of pixels in the display will change, the number of dots will not. If the panel is set to it's Native Resolution however, the number of pixels will equal the dot pitch. LCDs may be either Passive Matrix or Active Matrix. Monochrome displays in small devices such as PDAs and also older laptops use passive matrix technology which is either STN (Super-Twisted Nematic), DSTN (Double-layer STN) or CSTN (Color-STN). More recent devices, including current laptops and LCD televisions, use Active Matrix panels, also known as TFTs (Thin Film Transistor). | | | |
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