liquid crystal display

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Noun

liquid crystal display - a digital display that uses liquid crystal cells that change reflectivity in an applied electric field; used for portable computer displays and watches etc.LCDactive matrix screen - a type of LCD screen used for some portable computers; there is a separate circuit for each pixelalphanumeric display, digital display - a display that gives the information in the form of characters (numbers or letters)passive matrix display - a type of LCD display used for some portable computers; parallel wires run both vertically and horizontally and pixels are turned on when the wires intersecting at that pixel are both energized; "passive matrix displays are generally inferior to active matrix displays"

Translations

Flüssigkristallbildschirm

liquid crystal display

[′lik·wəd ′krist·əl di′splā] (electronics) A digital display that consists of two sheets of glass separated by a sealed-in, normally transparent, liquid crystal material; the outer surface of each glass sheet has a transparent conductive coating such as tin oxide or indium oxide, with the viewing-side coating etched into character-forming segments that have leads going to the edges of the display; a voltage applied between front and back electrode coatings disrupts the orderly arrangement of the molecules, darkening the liquid enough to form visible characters even though no light is generated. Abbreviated LCD.

liquid crystal display

(hardware)(LCD) An electro-optical device used to displaydigits, characters or images, commonly used in digitalwatches, calculators, and portable computers.

The heart of the liquid crystal display is a piece of liquid crystal material placed between a pair of transparentelectrodes. The liquid crystal changes the phase of thelight passing through it and this phase change can becontrolled by the voltage applied between the electrodes.If such a unit is placed between a pair of plane polariserplates then light can pass through it only if the correctvoltage is applied. Liquid crystal displays are formed byintegrating a number of such cells, or more usually, by usinga single liquid crystal plate and a pattern of electrodes.

The simplest kind of liquid crystal displays, those used indigital watches and calculators, contain a common electrodeplane covering one side and a pattern of electrodes on theother. These electrodes can be individually controlled toproduce the appropriate display. Computer displays, however,require far too many pixels (typically between 50,000 andseveral millions) to make this scheme, in particular itswiring, feasible. The electrodes are therefore replaced by anumber of row electrodes on one side and column electrodes onthe other. By applying voltage to one row and several columnsthe pixels at the intersections are set.

The pixels being set one row after the other, in passive matrix displays the number of rows is limited by the ratio ofthe setting and fading times. In the setup described above(known as "twisted nematic") the number of rows is limitedto about 20. Using an alternative "supertwisted nematic"setup VGA quality displays (480 rows) can be easily built.As of 1995 most notebook computers used this technique.

Fading can be slowed by putting an active element, such as atransistor, on the top of each pixel. This "remembers" thesetting of that pixel. These active matrix displays are ofmuch better quality (as good as CRTs) but are much moreexpensive than the passive matrix displays.

LCDs are slimmer, lighter and consume less power than theprevious dominant display type, the cathode ray tube, hencetheir importance for portable computers.

liquid crystal display

liquid crystal display

liquid crystal display

liquid crystal display

liquid crystal display

display

liquid crystal display

LCD

liquid crystal display

Synonyms for liquid crystal display

noun a digital display that uses liquid crystal cells that change reflectivity in an applied electric field

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