An active matrix liquid crystal display (AMLCD) is a type of flat panel display, currently the overwhelming choice of notebook computer manufacturers, due to low weight, very good image quality, wide color gamut and response time. The first functional AMLCD display was made by Dr T Peter Brody at Westinghouse Electric Corporation in 1973.[1]
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The most common type of LCD display contains, besides the polarizing sheets and cells of liquid crystal, a matrix of TFTs to make a TFT-LCD.[2] These devices store the electrical state of each pixel on the display while all the other pixels are being updated. This method provides a much brighter, sharper display than a passive matrix of the same size. An important specification for these displays is their viewing-angle.
Thin-film transistors are usually used for constructing an active matrix so that the two terms are often interchanged, even though a thin film transistor is just one component in an active matrix and some active-matrix designs have used other components such as diodes. Whereas a passive matrix display uses a simple conductive grid to deliver current to the liquid crystals in the target area, an active-matrix display uses a grid of transistors and capacitors with the ability to hold a charge for a limited period of time. Because of the switching action of transistors, only the desired pixel receives a charge, and the pixel acts as a capacitor to hold the charge until the next refresh cycle, improving image quality over a passive matrix.