Last modified on 26 June 2003.
Encyclopædia Galactica
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CCD-Camera
A camera that uses a charge-coupled device (CCD) to gather light of
the object being photographed and to transfer this information into
a computer in a digital format.
CCD: An electronic imaging device widely used in astronomical
applications. The CCD consists of semiconducting silicon; when
photons of light fall on it, free electrons
are released. To preserve the pattern of light falling on the CCD, the
photons are collected in a matrix of small picture array of electrodes,
called gates, formed on the surface of the CCD. The electric charge
in each pixel is then transferred to the ends of the rows by
systematically changing the voltages on each gate so that the charge
passes along as if on a conveyor belt. Finally, the electrons in
each little packet of charge from individual pixels are counted and
converted into a form which the whole image can be stored in a
computer or displayed on a television screen. (Mitton, 1993,
Dictionary of Astronomy, London: Penguin Books)
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Created by
Rami T. F. Rekola