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charge-coupled device
charge-coupled device (CCD) A silicon chip containing an array of light-sensitive diodes, used for capturing images. The photodiodes, arranged in an array of rows and columns, become charged when light falls on them. The amount of charge depends on the amount of light, which may be built up over time. These charges are read out column by column to provide an analogue signal of the image on the array, which is then converted to digital form for display and storage on a computer. CCDs are widely used both by professional and amateur astronomers as they are more sensitive to light than a photographic emulsion, give an output in almost constant proportion to the amount of light falling on them (i.e. a linear response), and have no reciprocity failure. The image can be displayed almost immediately after the end of the exposure, and image processing can be used to enhance it. However, the detector area is much smaller than a photographic plate or film, which can be of any size required and provides much finer resolution.
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"charge-coupled device." A Dictionary of Astronomy. 1997. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "charge-coupled device." A Dictionary of Astronomy. 1997. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O80-chargecoupleddevice.html "charge-coupled device." A Dictionary of Astronomy. 1997. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-chargecoupleddevice.html |
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charge-coupled device
charge-coupled device (CCD) Type of silicon chip designed to capture images. The CCD is divided into a number of microscopic areas (pixels), arranged in rows. When a photon hits a pixel, it knocks off an electron from a silicon atom, which becomes charged. An opposite charge in a layer on the base of the CCD confines this charged silicon atom, and in this way a charge builds up in each pixel relative to the number of photons hitting it 50 times a second. The contents of each pixel are read off, a row at a time, forming an electrical signal that can be used to create television pictures. CCDs are found in video cameras, fax machines, and digital cameras.
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"charge-coupled device." World Encyclopedia. 2005. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "charge-coupled device." World Encyclopedia. 2005. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O142-chargecoupleddevice.html "charge-coupled device." World Encyclopedia. 2005. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-chargecoupleddevice.html |
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charge-coupled device
charge-coupled device (CCD) A light-sensitive semiconductor used to enhance images obtained from faint objects. It accumulates and temporarily stores charge at particular pixel locations when struck by photons. The pixels can then be moved, allowing them to be pieced together to form an image.
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AILSA ALLABY and MICHAEL ALLABY. "charge-coupled device." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "charge-coupled device." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O13-chargecoupleddevice.html AILSA ALLABY and MICHAEL ALLABY. "charge-coupled device." A Dictionary of Earth Sciences. 1999. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-chargecoupleddevice.html |
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charge-coupled device
charge-coupled device See CCD.
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Cite this article
JOHN DAINTITH. "charge-coupled device." A Dictionary of Computing. 2004. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. JOHN DAINTITH. "charge-coupled device." A Dictionary of Computing. 2004. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O11-chargecoupleddevice.html JOHN DAINTITH. "charge-coupled device." A Dictionary of Computing. 2004. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O11-chargecoupleddevice.html |
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