TFT display modules are a viable solution for many consumer, commercial and industrial applications. Their combination of high resolution and fast refresh rate make them a great option for time sensitive uses in everything from multimedia, health monitoring, and industrial systems control.
TFT display modules use a popular LCD active matrix technology. LCD TFT, or liquid crystal display using thin film transistor technology, displays crisp and vibrant visuals for use in such consumer devices as computers, television, projection displays, mobile phones, digital assistants and hand held video games.
The active matrix display technology used in TFT display modules differs from passive matrix LCD used in calculators and digital watches. In passive matrix, voltage is applied to a pixel cell, altering the orientation of the liquid crystal. The pixel cell acts as a capacitor and holds this charge for a time. When used for rapidly changing graphics, this can lead to a variety of visual artifacts.
TFT display modules actively change the orientation of the liquid crystal from off to on to off again. This gives the display a much higher refresh rate and allows for the clear depiction of changing images and data.
The transistor layer of an TFT display module is made up of a thin film of semiconductor on top of a glass substrate. In a color TFT display module, each pixel is made up of a blue, red and green cell to produce the entire range of visible light. Each of these cells has it’s own transistor and liquid crystal material. Liquid crystal can change position quickly as a liquid but also has the ability to remain in an arranged crystalline position. In essence, each cell is a window with the transistor being the hand that opens the liquid crystal blinds to either release or withhold light. When millions of these cells work together, they produce a working image.
Early TFT display modules were of the reflective type. In these displays, ambient light enters the monitor and is reflected back by a surface behind the pixel matrix. This type of display works fine in good lighting conditions but suffers in low light. Most modern TFT display modules use some form of internal lighting to solve this problem.
Back lighting, side lighting and front lighting are all used to actively produce light in a TFT display module. CCFL, or cold cathode fluorescent lamps, are a commonly used solution. These fluorescents are very similar to overhead lighting used in offices and are inexpensive and replaceable. Advances in LED technology have made it possible to provide back lighting by a thin layer of light emitting diodes. These TFT display modules are very popular, although currently expensive option, with the technology being utilized in high price consumer televisions.
The basic technology behind TFT display modules has been in use for years and proven itself in a variety of conditions. By adopting new technology to address its shortcomings, TFT display modules have retained market importance and are a number one option for display devices for communications, office equipment, marine, industrial equipment, medical equipment, and other instrumentation.
