Active matrix
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 CdSe or Silicon-based thin-film transistor (TFT) for each pixel. The technology was invented and first demonstrated by hungarian emigréT Peter Brody and his Thin-Film Devices department at Westinghouse Electric Corporation in 1968, and the term was introduced into the literature in 1975.[1][2][3]
Given a m × n matrix, the number of connectors needed to address the display is m + 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 Transistors (TFT), i.e. a FET based on either the cheaper non-crystalline thin-film silicon (a-Si), polycrystalline silicon (poly-Si), or CdSe semiconductor material.
Another variant is to use diodes or resistors, but neither diodes (e.g. Metal insulator metal diodes), nor non-linear voltage dependent resistors (i.e. varistors) are currently used. The latter of these is not yet economical when compared to TFT.
See also
References
- ^ "Active Matrix". OED. Oxford University Press. 2011.
{{cite web}}: External link in|title=|url=(help)(subscription required) - ^ Castellano, Joseph A. (2005). Liquid gold : the story of liquid crystal displays and the creation of an industry ([Online-Ausg.] ed.). New Jersey [u.a.]: World Scientific. p. 176. ISBN 978-9812389565.
- ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1109/T-ED.1975.18214, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1109/T-ED.1975.18214instead.