What is LCD and how does it work?

Answer 1

In a LCD TV, liquid crystals are sandwiched between two transparent electrodes and two polarizing filters. In other words, liquid crystals (most often in nematic phase) are packed between two glass plates. Two grids of electrodes (one is horizontally aligned and another is vertically aligned) contact either side of the crystals. The job of this network of electrodes is to access each pixel of the crystal layer and control the electric flow.

Liquid crystals are not luminious by themselves and it is the backlight device made of fluorescent lamps which give off the light behind them. The light of the backlight is then diffused by a white panel before passing through the liquid crystals. This white panel ensures that the entire surface of the screen gets uniform brightness. The front panel of LCD is made up of a grid of wires which are in contact with each pixel of the screen and activate it separately.

With in network of crystals, each molecule functions like a gate to open or close the passage of light through them depending on the voltage of the current. To produce bright display, the voltage is kept low while for dark details the voltage is increased. By nature, liquid crystals always allow a smaller amount of light to pass through them making the pure black levels somewhat impossible.

Answer 2

LCD monitors, as their name suggests, use liquid crystal display (LCD) technology, making it far different from the ordinary CRT monitor. An LCD is a thin and flat display device composed of pixels arrayed in front of a light source or reflector. LCDs, in turn, use liquid crystals, which were first discovered in 1888. These crystals are actually liquid chemicals that align perfectly when subjected to electrical fields; when they're properly aligned, they allow light to pass through them. LCDs use this property by using electrical currents to align the crystals and allow varying levels of light to pass through and create the desired images and colors. To be more technical, the liquid crystals are sandwiched between two pieces of polarized glass ("substrate"). The fluorescent light source, also known as the backlight, emanates light that passes through the first substrate. The electrical currents then cause the crystals to align, allow varying levels of light to pass through to the second substrate. The end result is what you see onscreen. LCDs can use either active-matrix or passive-matrix structure. Most LCD monitors, along with LCD TVs, use active-matrix.

Answer 3

seminarThe Bastards Liquid crystal display technology works by blocking light. Specifically, an LCD is made of two pieces of polarized glass (also called substrate) that contain a liquid crystal material between them. A backlight creates light that passes through the first substrate. At the same time, electrical currents cause the liquid crystal molecules to align to allow varying levels of light to pass through to the second substrate and create the colors and images that you see.

Active and Passive Matrix Displays Most LCD displays use active matrix technology. A thin film transistor (TFT) arranges tiny transistors and capacitors in a matrix on the glass of the display. To address a particular pixel, the proper row is switched on, and then a charge is sent down the correct column. Since all of the other rows that the column intersects are turned off, only the capacitor at the designated pixel receives a charge. The capacitor is able to hold the charge until the next refresh cycle.

Photo courtesy Sony Sony flat-panel display

The other type of LCD technology is passive matrix. This type of LCD display uses a grid of conductive metal to charge each pixel. Although they are less expensive to produce, passive matrix monitors are rarely used today due to the technology's slow response time and imprecise voltage control compared to active matrix technology.

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Answer 4

LCD stands for "Liquid Crystal Display".

There is literally an encapsulated liquid that shifts polarity when a small current is applied. When the crystal is polarized in a specific orientation, polarized light will not pass (because of a polarizing filter either behind or in front of the crystal)

Now, duplicate that crystal thousands of times, with each crystal representing a dot, or pixel on the monitor, and put a "backlight" behind the crystals.

If you'll look closely you will see that the crystals have different colors, and each will fire according to the requirements of the picture.

Answer 5

LCD stands for Liquid Crystal Display. Within the product are two panels which are separated by a liquid crystal solution. The crystals in the liquid either block light or allow it to pass through, thus forming the image you look at on your screen.

Answer 6

There are many types of industrial lcd displays. here is a link about how touch screen ones operate... http://www.industrial-lcd.com/index.php?option=com_content&view=article&id=21:faq&catid=3:text&Itemid=20#3

Answer 7

LCD's (Liquid Crystal Displays) work by the crystals being charged with an electric current in varying degrees producing different wave-lengths of light.

Answer 8

Liquid Crystal Display screens work by manipulating the many liquid crystals and electrodes present in the system. These liquid crystals do not emit light directly.