A sectional view of an image orthicon is shown in the below figure. It has three main sections: image section, scanning section and electron. Image orthicon definition, a camera tube, more sensitive than the orthicon, in which an electron image generated by a photocathode is focused on one side of a. The image orthicon (10) was developed during World War II to solve some of the problems of its predecessors in the camera-tube family. These included.
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University of California Press. A review of some television pick-up tubes. Each individual electron from the electron image produces several secondary electrons after reaching the target, so that an amplification effect is produced.
The electron image produced tubw the photocathode is made to move towards the target plate located at a short distance from it. So many may be ejected that the corresponding point on the collection mesh can no longer soak them upand thus they fall back to nearby spots on the target instead, much as water splashes in a ring when a rock is thrown into it. As a precaution against light leakage, which has been shown to cause spurious results, the gun end of the cajera is coated with an opaque enamel.
The face of the target remote from the photo-cathode is scanned by an electron beam emanating from a triode electron gun, the potentials being so adjusted that the beam approaches the target with a substantially zero velocity and is, therefore, unable to produce unwanted secondary electrons.
The latter is essentially a magnetic lens ; it focuses the “crossover” between the CRT’s cathode and G1 electrode, where the electrons pinch together and diverge again onto the screen. The camera pickup tubes described in this article are also CRTs, but they display no image.
Views Read Edit View history. Zworykin, pioneer of television.
Video camera tube
It has tubw efficient photocathode that transforms the scene light into an electron image; the latter is then accelerated towards a target specially prepared for the emission of secondary electrons. This effect was actually “cultivated” by tube manufacturers to a certain extent, as a small, carefully controlled amount of the dark halo has the effect of “crispening” the visual image orthhicon to the contrast effect.
In JanuaryAmerican inventor and television pioneer Philo T. The output from the detector is an electric current whose magnitude is a measure of the brightness of the corresponding area of the image.
Early color cameras used the obvious technique of using separate red, green and blue image tubes in conjunction with a color separatora technique still in use with 3CCD solid state cameras today.
New TV Camera Tube. It uses a vertically striped RGB color filter over the faceplate of an otherwise standard vidicon imaging tube to segment the scan into corresponding red, green and blue segments. Therefore, secondary electrons are emitted from the surface of the isolating material when the electron image reaches the target, and the resulting positive charges are stored directly onto the surface of the isolated material.
The return beam, comprising electrons which are not required for neutralising the charge on the target, travels back along approximately the same path as the outgoing electron beam and is directed into a five-stage electron multiplier where it is amplified to become the output video signal.
The scene image is projected onto an efficient continuous-film semitransparent photocathode that transforms the scene light into a light-emitted electron image, the orthicin is then accelerated and focused via electromagnetic fields towards a target specially prepared for the emission of secondary electrons.
Compared to Saticons, Plumbicons have much higher resistance to burn-in, and comet and trailing artifacts from bright lights in the shot.
Archived from the original on June 22, The electrical charge produced by an image will remain in the face plate until it is scanned or until the charge dissipates. This technology was a precursor to modern microbolometer technology.
This tube is essentially identical to the super-Emitron, but the target is constructed of a thin layer of isolating material placed on top of a conductive base, irthicon mosaic of metallic granules is missing.
As a result, the Trinicon featured a larger dynamic range of operation. Step to home television. The super-Emitron is a combination of the image dissector and the Emitron.
Image Orthicon Camera Tubes
It is used mostly in low-end consumer cameras, though Sony also used it in some moderate cost professional cameras in the s, such as the DXC and BVP-1 models. Dictionary of Video and Television Technology.
However, it tends to flare in bright light, causing a dark halo to be camsra around the object; this anomaly is referred to as ” blooming ” in the broadcast industry when image orthicon tubes were in operation. Each globule is very active photoelectrically and constitutes, to all intents and purposes, a minute individual camefa cell”. In a letter to Nature published in OctoberCampbell-Swinton also announced the results of some “not very successful experiments” he had conducted with G.
The resultant current was dependent on the brightness of the image on the target. Its surface consists of selenium with trace amounts of arsenic and tellurium added SeAsTe to make the signal more stable.
The center think local axis of one of those helices is like a line of force of the magnetic field. Only they could provide sufficient detail. The method of extracting the color is similar however. An International History of the Formative Years. Dieckmann and Hell submitted their application to the German patent office in Apriland a patent was issued in October