TFT displays competed directly with the CRT market to claim dominance in the display market. With their more efficient use of power and smaller footprint, they have become commonplace in the computing world.

Unlike CRT which uses a large electron gun to scan lines onto a reactive screen, a TFT uses a stain-glass method of display. The pixel elements operate independently to the lighting source.

Essentially, they have a plate of coloured pixels which can be changed depending on the image that is sent to the monitor. This, in itself, wouldn’t show any image as there is no light produced by this plate. To overcome this, a blacklight is needed. This is usually supplied by a sheet of plastic or glass which has either one or two (some have more) fluorescent bulbs running along the top and bottom. The transparent sheet evenly distributes this light across the entire display providing a backlight.

The use of fluorescent bulbs require high voltages which is supplied by a small inverter which can produce dangerous voltages if used outside of the normal operating parameters. The inverter is the most power hungry part of the display.

As there is no electron gun, and the elements of the display are in plate form, there is no need for the depth that CRT monitors require. Instead they can be manufactured thin, hence the name flat screen monitors. This name also refers to the shape of the front of the monitor. Originally, CRT’s could only use a convex glass front which will show distortion. Later models overcame this issue but thin lines are visible across the unit is such displays.

TFT’s also use a DVI input which means that the signal from the computer stays digital throughout its progress from graphics card to display removing any artefacts that may arise. DVI also allows higher resolution output compared to VGA.

While a thinner display is possible, there are several downsides compared to the older CRT technology. Most importantly is the refresh rate. This is measured in the time a pixel takes to go from white to black (or grey to grey). The longer this takes, the more ghosting and blurring occurs during fast paced on screen action. Gamers usually operate in such an environment and hence choose high responsive units.

Another minor issue is the colour balance. CRT’s are still widely used in the media business as they are often provide a more faithful colour reproduction compared to TFT’s. Also, TFT’s have a native resolution which when supplied, shows a perfect pin sharp picture. Once the resolution dips below this native resolution, the screen must interpolate and filling in the pixels where there is no information. This results in on screen blocks and misshapen images. CRT’s deal with varying resolutions much better than TFT’s although high-spec TFT’s use more effective algorithms.