Active matrix: Difference between revisions

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'''Active matrix''' is a type of [[addressing scheme]] used in [[flat panel displays]]. The term describes a method of switching individual elements of a [[flat panel display]], using a [[Cadmium selenide|CdSe]] or [[Silicon]]-based [[thin-film transistor]] (TFT) for each [[pixel]]. The technology was invented and first demonstrated by hungarianHungarian emigré [[T Peter Brody]] and his Thin-Film Devices department at [[Westinghouse Electric Corporation]] in 1968, and the term was introduced into the literature in 1975.<ref name=OEDActiveMatrix>{{cite web|title=[http://www.oed.com/viewdictionaryentry/Entry/1953#eid19485882 Active Matrix]|year=2011|work=[[OED]]|publisher=[[Oxford University Press]]}}{{subscription required}}</ref><ref name=Castellano>{{cite book|last=Castellano|first=Joseph A.|title=Liquid gold : the story of liquid crystal displays and the creation of an industry|year=2005|publisher=World Scientific|___location=New Jersey [u.a.]|isbn=978-9812389565|pages=176|url=http://www.amazon.com/Liquid-Gold-Displays-Creation-Industry/dp/9812389563|edition=[Online-Ausg.]}}</ref><ref>{{cite doi|10.1109/T-ED.1975.18214}}</ref>

Given a ''m''&nbsp;&times;&nbsp;''n'' matrix, the number of connectors needed to address the display is ''m''&nbsp;+&nbsp;''n''. Each [[pixel]] is attached to a switch-device, which ''actively'' maintains the pixel state while other pixels are being addressed, which also prevents [[crosstalk]] from inadvertently changing the state of an unaddressed pixel. The most common switching devices are [[Thin Film Transistor|Thin Film Transistors (TFT)]], i.e. a [[field effect transistor|FET]] based on either the cheaper [[amorphous|non-crystalline]] [[thin-film]] [[silicon]] ([[amorphous silicon|a-Si]]), [[polycrystalline]] silicon ([[polycrystalline silicon|poly-Si]]), or [[Cadmium selenide|CdSe]] [[semiconductor]] material.