Introduction
A TFT monitor is a kind of LCD (Liquid Crystal Display) monitor that uses thin-film transistor (TFT) technology. As we are aware, LCD monitors are fast becoming the norm in place of cathode ray tube (CRT) monitors. While there are also other technologies in use, TFT is the technology most LCD monitors use.
Why TFT?
In TFT technology, a separate miniscule transistor works for each pixel on the display. As the transistors are so tiny, the charge required to operate it is very small too. This way, the display gets refreshed several times per second, ensuring great visual clarity.
In Passive Matrix LCD monitors that were in use before TFT, fast moving images could not be represented with adequate clarity. For instance, a body in motion from point A to point B would disappear between the two rest points. TFT could meet this challenge as each pixel is backed up with a transistor, and thus track the body throughout the screen. Thus TFT monitors are ideal for games, video displays and everything involving multimedia.
Dead Pixels- the Hitch
Let us consider a standard 17 inch TFT monitor. Its area typically covers about 1.3 million pixels and as many tiny transistors to back them up. This scenario creates a high probability for some of the transistors (may be one or two) not working or malfunctioning. This leads to the corresponding pixels not working, leading to ‘dead pixels’. In other words a dead pixel is a pixel whose transistor is inactive. A dead pixel does not show its part of the display image. As we can see, the more the dead pixels, the less is the picture quality.
Now the question arises as to how we can recognize a dead pixel. A dead pixel shows as a tiny red, white or blue dot against the black background of the monitor when there is no picture on display.
If you are lucky enough, you will get a TFT monitor with no dead pixels. Even if you have a dead pixel or two on your monitor, that need not affect your viewing pleasure unless they are located in a critical location on the screen. For instance, a dead pixel close to the boarder of the frame need not affect the picture quality in a big way. All said and done, you cannot hope for a manufacturer to replace your TFT monitor unless it has 11 or more dead pixels.
The failure prospect of having so many transistors at work is an accepted fact among TFT manufacturers. Most TFT factories are selective about the brands for which they manufacture panels. As a rule, one portion of the displays come out without dead pixels, some contain a small acceptable number of dead pixels while others have to be rejected outright owing to the large number of dead pixels. The panels with some (acceptable) dead pixels usually go into discount models.
What You can Do
While shopping for a TFT monitor, read feedback from buyers at online retail sites. This will help you to compare several brands and get an idea of which brands generally provide good display quality.
As we saw earlier, TFT monitors are excellent for clear text, vivid color and better response time for multimedia applications. If you are likely to use your system for gaming, graphic/ video editing and other multimedia applications, you would do well to go for a TFT monitor with a response rate of 16 ms or less. Another feature to look for is the digital visual/ video interface (DVI). |
