A sectional view of an image orthicon is shown in the below figure. It has three main sections: image section, scanning section and electron. Historical information about the start of the first television camera tubes. The huge 4,5″ EEV Image Orthicon with in front a 2/3″ Vidicon tube. This EEV. This chapter discusses television X-ray image intensifiers that use an image orthicon camera tube of the type used in many television studios. The electrostatic.
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@ The Valve Museum
This necessitated an additional electrode buried in the target to detect where the scanning electron beam was relative to the stripe filter. Electrons inside these long focus coils take helical paths as they travel along the length of the tube.
Successive stages of the electron multiplier are arranged symmetrically around and back of the first stage. Principles of Operation Schematic arrangement of the 4. Retrieved March 14, Early Television Foundation and Museum.
Indeed, it was the representative of the European tradition in electronic tubes competing against the American tradition represented by the image orthicon.
These tubes were used for broadcast quality pictures in the most expensive cameras of the s and s.
A sharply focused beam of electrons a cathode ray is generated by the electron gun at ground potential and accelerated by the anode the first dynode of the electron multiplier around the gun at a high positive voltage approx. Secondary electrons tybe produced by the impact of the photo-electrons on the target and these are collected by the fine mesh screen which is held at a definite small positive potential with respect to the target.
Fast as a movie camera. This eliminates any possibility of secondary emission from this side of the target plate.
January 10,p. On average, each image electron ejects several “splash” electrons thus adding amplification by secondary emissionand these excess electrons are soaked up by the positive mesh effectively removing electrons from the target and causing a positive charge on it in relation to the incident light in the photocathode.
During the s and s, field-sequential color systems were developed which used synchronized motor-driven color-filter disks at the camera’s image tube and at the television receiver. New TV Imags Tube. Once the image electrons reach the target, they cause a “splash” of electrons by the effect of imaage emission.
Archived from the original on 17 August If the three levels were the same, then that part of the scene was green. The photosensitive target in these tubes suffered from the limitation that the light level had to rise to a particular level before any video output resulted.
For instance, a 6. The grid 4 voltage is adjusted to produce uniform deceleration of electrons for the entire target area.
This section does not cite any sources. One technique has already been described Trinicon above. That is, giving the illusion of being more sharply focused than it actually is. The optical system of the image dissector focuses an image onto a photocathode mounted inside a high vacuum. The target end of the wall coating grid No.
Radio and Communication Engineering, volume 97, issue Navythe tubee tubes being delivered in January In addition to improving the landing characteristics of the beam at the target, the presence of the field correcting mesh reduces the intensity of the white edging typical of pictures produced by earlier imagr of the image orthicon.
Inwhile employed by the Westinghouse Electric Corporation in Pittsburgh, Pennsylvania, Russian-born American engineer Vladimir Zworykin presented a project for a totally electronic television system to the company’s general manager.
Originally developed by Toshiba in as chalniconPasecon is a registered trademark of Heimann GmbH from Type was first introduced in Zworykin, pioneer of television. An image of the scene to be televised is focused by an optical lens system on to the photo-cathode and causes photo-electrons to be emitted. The electron optics of camera tubes differ considerably.
Afterand the introduction of the diode-gun Plumbicon tube, the resolution of both types was so high, compared to the maximum limits of the broadcasting standard, that the Saticon’s resolution advantage became moot.
Newvicon is a registered trademark of Matsushita from Each globule is very active photoelectrically and constitutes, to all intents and purposes, a minute individual photoelectric cell”.
The electron gun structure produces a beam of electrons that is accelerated towards the target. 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. Light biasing was a method whereby the photosensitive target was illuminated from a light source just enough that no appreciable output was obtained, but such that a slight increase in light level from the scene was enough to provide discernible output.
A description of a CRT imaging device also appeared in a patent application filed by Edvard-Gustav Schoultz in France in Augustand published in although a working device was not demonstrated until some years later.