LCD Panel

What are TFT-LCDs?

TFT-LCD stands for thin-film transistor liquid-crystal display.

TFT-LCD was first invented in early 1960’s over the years substantial improvements were made on it and by 1991, it was developed for the commercial production of notebook computers. Thus the TFT-LCD industry was born.

The TFT-LCD Structure:

It uses liquid crystal to control the passage of light. The basic structure of a TFT-LCD panel may be thought of as two glass substrates sandwiching a layer of liquid crystal. The front glass substrate is fitted with a color filter, while the back glass substrate has transistors fabricated on it. When voltage is applied to a transistor, the liquid crystal is bent, allowing light to pass through to form a pixel. A light source is located at the back of the panel and belongs to a backlight unit. The front glass substrate is fitted with a color filter, which gives each pixel its own color. The combination of these pixels in different colors forms the image on the panel.

TFT Pixel Element

A TFT array is composed of a matrix of pixels and ITO region (a transparent electric conducting film)each with a TFT device and is so called array. Thousands or millions of these pixels together create an image on the display. The diagram below shows the simple structure of a pixel

No matter how the design of the TFT panel has been changed or modified, its structures have to contain TFT devices and LC control region (ITO film for transmissive type of LCD, metal such as AI is used for reflective type of LCD).

TFT device is a switching device, which functions to turn each individual pixel on or off hence control the number of electrons flow into the ITO zone. As the number of electrons reaches the expected value, TFT turns off and these electrons can be kept within the ITO zone.

The above diagram shows the flow of electricity for a TFT substrate, during time t1 to tn gate line driver IC continuously chooses to open G1 and allows each source line to charge the TFT pixel which lies along G1 starting from D1, D2 to Dn. Once completed, the gate line driver IC then chooses to open G2 and the process is repeated.

LCD Lighting Theory

Liquid crystal, lying between TFT substrates and CF substrates, will rotate into different angles according to the charges applied to each pixel. When millions of pixels are charged differently, we could obtain millions of LC angles within the area.

The reason why we need to control the LC’s standing angle lying within millions of pixels is that we need to use LC’s optic rotation nature to control the amount of light passing through the LCD panel. As shown at the following diagram, light from the back light module travels from the TFT panel through ITO electrode, turned by Liquid Crystal and reaches the LCD panel on the top.

A few things can be discovered from the above diagram:

LC angles control the amount of light being rotated. From the above example: the bigger the standing angle the less the light passes through the top substrate.
Light not rotated by LC will be absorbed by the top polarizer. In the Natural world, light travels in random directions; the function of polarizer is to filter most of them and allows only certain light with desired direction to pass through.

written by admin

The appeal of LCD (Liquid Crystal Display) monitors is rapidly growing in the market. With the advance of technology LCD are absolutely accustomed to computer users and we can see a lot of them are application LCD. It would be a claiming for LCD accomplishment companies to accomplish the growing appeal of LCD in the market.

Some allegory amid LCD adviser and CRT adviser is accustomed below
1. LCD panels are alone an inch blubbery after including the stand. These absorb beneath ability and don’t allow a lot of calefaction if used, clashing CRT monitor.
2. Their agenda affectation is bluff and aftermath acceptable superior account as analyze to CRT monitor.
3. An LCD adviser is abbreviate and comes in a actual bunched configuration. They can be fit calmly into any beneath abandoned allotment of the allowance or anywhere. They are actual acceptable for baby offices or homes
4. But it’s difficult for anybody to allow LCD affectation because LCD affectation screens or monitors are absolutely big-ticket as analyze to CRT
5. LCD screens or displays are actual acute and should be administration with care. They are not acceptable for accessory used.
6. As far as affective images or 3D images are concern, LCD screens are bleared and unclear. Hence, anyone prefers CRT over LCD screens. Clear designers adopt the CRT over the LCD. Not alone that, the blush gradations are not bright in the LCD panel, and it causes problems in appropriate amid darker shades, creating applied problems for clear designers.

written by admin \\ tags: Crystal, Display, LCD, Liquid

Liquid crystal display monitors have taken the computer industry by storm. To own a glassy and attenuate LCD screens has become a cachet attribute a part of computer users. Manufacturers beyond the apple are aggravating to cycle out this bunched adviser to accomplish the growing appeal for this beautiful and high-quality image-producing product.
Unlike CRT monitors, the LCD panels are alone an inch blubbery after including the stand. These absorb beneath ability and don’t afford a lot of calefaction if used. Moreover, they are accepted because of their bluff agenda display. An agenda affectation will beating off the acid ghosting aftereffect and bear aciculate account quality.
An LCD screen has an actual bunched configuration. This gives a clearer account and adds to the ball of watching movies or videos on the screen. Its condensed admeasurements’ enables it to fit calmly into beneath ample places, authoritative it the absolute best for baby offices or homes.
LCD display screens or monitors are absolutely expensive, which makes it difficult for anybody to accept it aloft the affordable CRT. You may accept to carapace out $300 for a 15-inch LCD monitor, admitting for a 17-inch CRT adviser you pay alone about $100.
The accustomed CRT adviser is actual athletic and will not crumble beneath accessory abrasion and breach while in use. On the added hand, the LCD screens are acutely brittle and need to be handled carefully.
The 3D images of an LCD screens are bleared and cryptic if the altar on the screen is moving. Hence, gaming enthusiasts adopt CRT over LCD screens. Clear designers adopt the CRT over the LCD. Furthermore, the blush gradations are not bright in the LCD panel, and it poses problems in appropriate amid darker shades, creating applied problems for clear designers.

written by admin

With the hot new LCD monitors on the bazaar out there a lot of people are not acquainted of some of the disadvantages and added affliction they crave to accumulate those abiding as continued as the old CRT monitors could last.
Liquid Crystal Displays are a lot added acute afresh the old Cathode Ray Tubes were. CRT screens are fabricated of a blubbery bottle that can yield added corruption afresh the artificial LCD’s.
Cleaning a CRT Screen was absolutely simple just use Windex or Pledge with a cardboard anhydrate and it was cleaned. LCD monitors about accept an anti-reflecting blur blanket on the alfresco of the awning that can be eaten abroad by ammonia based cleaners. This will accomplish your LCD attending blurred and accept bleared regions of your computer. The cardboard anhydrate and added copse based articles can additionally blemish the artificial as it is beneath abiding afresh the old bottle ones.
To apple-pie an LCD adviser about-face it off, artlessly wet a lint free cloth with water, afresh clean the monitor. Do not use the water directly to the LCD Screen as added water could soak/drip into additional crevices in your monitor.
Use a screen saver! It has the ability to save your LCD screen. A LCD screen is fabricated up of an arrangement of tiny pixels that affects the colors on your screen. If an LCD screen is larboard on for continued periods of time the images of your desktop accomplishments or whatever is larboard accessible will in fact bake into the artificial on the monitor. Now if you change your accomplishments to say a solid color it will in fact appearance you an outline of the antecedent accomplishments angel ghosted into it. The acceptable account is that this blazon of accident is reversible. You can about-face the accident by axis your adviser off as abundant as accessible and by active a screen saver that cycles colors and varies the achievement to the screen. This will ultimately go away.
Try not touching your LCD monitor; keep your hands off your screen. If you administer any array of burden to an LCD screen you accident damaging one of the pixels. If this happens the pixel will about-face assuredly black and it will never plan again. I’ve heard of people aggravating to beating out the pixel to get it to plan but I don’t acclaim this as you accident damaging added pixels. If your pixel is burnt into a specific color, I’ve also heard of programs that cycle through all colors and try to fix the problem. If this is the case afresh it’s absolutely worth the try.

written by admin \\ tags: LCD, Monitors