vidicon

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vidicon

(vid -ă-kon) A sensitive semiconductor-based instrument derived from television technology and used in astronomy for detecting and measuring light, ultraviolet, and near-infrared radiation. The target area is photosensitive, responding to the radiation falling on it by producing an electronic signal that varies linearly with the intensity of the incident radiation. The vidicon has been superseded by CCD detectors.

Vidicon

 

a television camera tube with a photoconductive target consisting of a photoresistor. Under the effect of the light coming from the image, electrical charges accumulate on the target (photoelectric cathode) of the vidicon: the resistance of individual sections of the target changes, and an irregular distribution of electrical potential (so-called potential relief), precisely duplicating the brightness distribution of the individual parts of the image, is created. These charges are scanned by a beam of electrons that is formed and deflected by magnetic and electrostatic fields. The idea of such a tube was suggested in 1925 by a Soviet engineer, A. A. Chernyshev; the first Soviet operational models appeared in 1950.

The target is made of thin (about 5 microns) layers of semiconductive materials: amorphous selenium, antimony trisulfide, and lead oxide with an admixture of lead sulfide, as well as germanium and silicon. The vidicon is noted for its simplicity of design and operation, low internal electrical noise, and small dimensions and for the absence of parasitical signals and halos. Because of persistence in its target, the vidicon is used in industrial television facilities and in the transmission of motion pictures on television, where the transmission of images of quickly moving objects is not required.

REFERENCE

Vlasov, V. F. Elektronnye i ionnye pribory, 3rd ed. Moscow, 1960.

G. I. KURENKOV

vidicon

[′vid·ə‚kän]
(electronics)
A camera tube in which a charge-density pattern is formed by photoconduction and stored on a photoconductor surface that is scanned by an electron beam, usually of low-velocity electrons; used chiefly in industrial television cameras.