orthicon

or·thi·con

O0128200 (ôr′thĭ-kŏn′)n. An electron tube used in early video cameras to capture images by scanning a photoactive mosaic inside the camera with a low-velocity electron beam. Unlike the earlier iconoscope, it could capture images in low light. Also called image orthicon.

[orth(o)- + icon(oscope).]

orthicon

(ˈɔːθɪˌkɒn) n (Electronics) a television camera tube in which an optical image produces a corresponding electrical charge pattern on a mosaic surface that is scanned from behind by an electron beam. The resulting discharge of the mosaic provides the output signal current. See also image orthicon[C20: from ortho- + icon(oscope)]

or•thi•con

(ˈɔr θɪˌkɒn)

also or•thi•con•o•scope

(ˌɔr θɪˈkɒn əˌskoʊp)

n. a television camera tube in which a beam of low-velocity electrons scans a photoemissive mosaic. [1935–40]

Thesaurus

Noun

orthicon - a now obsolete picture pickup tube in a television camera; electrons emitted from a photoemissive surface in proportion to the intensity of the incident light are focused onto the target causing secondary emission of electronsimage orthicontelevision pickup tube, television-camera tube - a tube that rapidly scans an optical image and converts it into electronic signals

Orthicon

enUK

orthicon

[′ȯr·thə‚kän] (electronics) A camera tube in which a beam of low-velocity electrons scans a photoemissive mosaic that is capable of storing a pattern of electric charges; has higher sensitivity than the iconoscope.

Orthicon

a television camera tube with a mosaic photocathode, in which the light image is converted into an electric image that is read by a beam of low-velocity electrons (secondary emission coefficient 1). The orthicon was proposed in 1939 by the American engineers. A. Rose and H. lams.

The image being transmitted is projected onto the target of the orthicon, which is a thin glass plate coated on the object side with a semitransparent, electrically conductive layer that serves as the signal plate; on the projector side the plate is coated with a fine-grained photoactive layer that is the mosaic photocathode. The photocurrent charges the elementary capacitors formed by the grains of the mosaic and the signal plate and thus forms a charge image on the surface of the target. Periodic discharge of the capacitors is brought about by an electron beam that scans the mosaic side of the target in a line-by-line pattern. At the same time, a video signal is formed in the circuit of the signal plate.

The transfer characteristic of an orthicon is almost linear over the whole operating range of illumination intensities. An orthicon is about 20 times more sensitive than an iconoscope, mainly because the photocurrent is used more efficiently in an orthicon. In the 1950’s the orthicon was replaced by the more advanced superorthicon.

A. A. ZHIGAREV

orthicon

or·thi·con

orthicon

or•thi•con

also or•thi•con•o•scope

Orthicon

orthicon

Orthicon

orthicon

Synonyms for orthicon

noun a now obsolete picture pickup tube in a television camera

Synonyms

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