liquid crystal display

(redirected from LCD Screen)
Also found in: Dictionary, Thesaurus, Medical.

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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

liquid crystal display

(hardware)
(LCD) An electro-optical device used to display digits, characters or images, commonly used in digital watches, calculators, and portable computers.

The heart of the liquid crystal display is a piece of liquid crystal material placed between a pair of transparent electrodes. The liquid crystal changes the phase of the light passing through it and this phase change can be controlled by the voltage applied between the electrodes. If such a unit is placed between a pair of plane polariser plates then light can pass through it only if the correct voltage is applied. Liquid crystal displays are formed by integrating a number of such cells, or more usually, by using a single liquid crystal plate and a pattern of electrodes.

The simplest kind of liquid crystal displays, those used in digital watches and calculators, contain a common electrode plane covering one side and a pattern of electrodes on the other. These electrodes can be individually controlled to produce the appropriate display. Computer displays, however, require far too many pixels (typically between 50,000 and several millions) to make this scheme, in particular its wiring, feasible. The electrodes are therefore replaced by a number of row electrodes on one side and column electrodes on the other. By applying voltage to one row and several columns the 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 of the setting and fading times. In the setup described above (known as "twisted nematic") the number of rows is limited to 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 a transistor, on the top of each pixel. This "remembers" the setting of that pixel. These active matrix displays are of much better quality (as good as CRTs) but are much more expensive than the passive matrix displays.

LCDs are slimmer, lighter and consume less power than the previous dominant display type, the cathode ray tube, hence their importance for portable computers.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

LCD

(Liquid Crystal Display) A screen display technology developed in 1963 at the David Sarnoff Research Center in Princeton, NJ. All computer and most TV screens are LCDs (see LED TV), while mobile device screens may be LCD or organic LED (see OLED). By the 1990s, color LCDs helped laptop sales boom, and LCD computer monitors outsold CRTs for the first time in 2003. See liquid crystal, LCD types and LCD categories.


A Color Pixel
Sandwiched between polarizing filters and glass panels, rod-shaped molecules of liquid crystals flow like liquid and bend light like crystal. The liquid crystal layer is 5 to 25 micrometers thick (2 to 10/10,000" inch). For more details on color LCDs, see LCD subpixels.







Seven-Segment LCD Watch
Because it took so little power to move crystal molecules, LCD wristwatches and other monochrome screens began to flourish in the late 1970s. For more details on this type of display, see seven-segment display. (Image courtesy of the private collection of Peter Wenzig.)







LCD vs. LED
LCDs and LEDs are widely used in combination as in this printer panel. Readouts are LCDs, but the indicator lights on billions of products are LEDs. LCD TVs use LED backlights (see LED and LED TV). See LCD vs. OLED and LCD vs. plasma.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
The printer's viewable LCD screen (2.62" x 1.31")-significantly large for its category-shows five lines of a label design at a given time and provides an easy-to-read, high resolution display (256x128 pixels).
Abdulwahab Al Sa'afan of Al Naseem School was awarded player of the match award which was also an LCD screen TV.
When checking the product by the ESD interference of 2-kV, 4-kV, 6-kV in the mode of contact discharge, keystroke zone and LCD screen would be invalidation or flicker at the level of 2 kV ESD, when the discharge voltage exceeds 2 kV, the electronic dictionary would be reset, as shown in Table 1.
According to the company, the GETAC V100 features an LCD screen that transforms from a notebook into a tablet PC, as well as a Sunlight-Readable LCD display of 1200cd/msq, the highest in the industry.
Poll results immediately display on the teacher's receiver LCD screen, and sessions can be wirelessly stored in the receiver or downloaded via USB cable to a PC with ResponseCard Anywhere desktop software.
The SmartView Nano, at 3.7 ounces and less than an inch thick, is both portable and powerful, with magnification from 5X to 20X and a 1.8inch color LCD screen. The Nano runs on three rechargeable AAA batteries and can be used for approximately three hours of continuous use.
Two new compact, lightweight, portable spectrophotometers in a vertical format boast advanced features such as Bluetooth wireless communication and a color LCD screen Models CM-700d and CM600d from Konica Minolta Sensing Americas.
Bushnell's Digital Trail Scout Viewer has a 2.5-inch color LCD screen and is capable of playing video clips with audio.
The system has a flat-panel LCD screen, which is attached to a moveable cart.
Entry level GE digital cameras start with 7 megapixel resolution and 2.5-inch LCD screens. Higher-end models offer up to 12 megapixels of resolutions and a 3-inch LCD screen.
Features include a control panel, high-end computer with DVD, VCR, visualizer, laptop connection, a PA audio system with microphone and speakers, and an interactive 17-inch LCD screen with interactive pen and annotation software.
A 3-inch, flip-up LCD screen identifies eight faces for sharper pictures and helps you shoot from those creative but difficult-to-reach angles (like the ones that make you look 20 pounds thinner).