Cathode Ray Tube

The cathode ray tube (CRT) is a vacuum tube containing an electron gun (a source of electrons or electron emitter) and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms (oscilloscope), pictures (television, computer monitor), radar targets and others. CRTs have also been used as memory devices, in which case the visible light emitted from the fluoresecent material (if any) is not intended to have significant meaning to a visual observer (though the visible pattern on the tube face may cryptically represent the stored data).

The CRT uses an evacuated glass envelope which is large, deep (i.e. long from front screen face to rear end), fairly heavy, and relatively fragile. As a matter of safety, the face is typically made of thick lead glass so as to be highly shatter-resistant and to block most X-ray emissions, particularly if the CRT is used in a consumer product.

CRTs have largely been superseded by more modern display technologies such as LCD, plasma display, and OLED, which as of 2012 offer lower manufacturing and distribution costs.

The vacuum level inside the tube is ultra-high vacuum on the order of 0.01 Pa to 133 nPa.

A cathode ray tube is a vacuum tube which consists of one or more electron guns, possibly internal electrostatic deflection plates, and a phosphor target. In television sets and computer monitors, the entire front area of the tube is scanned repetitively and systematically in a fixed pattern called a raster. An image is produced by controlling the intensity of each of the three electron beams, one for each additive primary color (red, green, and blue) with a video signal as a reference. In all modern CRT monitors and televisions, the beams are bent by magnetic deflection, a varying magnetic field generated by coils and driven by electronic circuits around the neck of the tube, although electrostatic deflection is commonly used in oscilloscopes, a type of diagnostic instrument.

Read more about Cathode Ray TubeOscilloscope CRTs, Color CRTs, Vector Monitors, CRT Resolution, Gamma, Security Concerns, Recycling, Advantages and Disadvantages

Other articles related to "ray, cathode ray tube":

Thomas T. Goldsmith, Jr. - The First Arcade Game With A CRT
... Patent 2,455,992, filed by Goldsmith and Estle Ray Mann in 1947, describes what may be the world's first cathode ray tube based game and patent, and was inspired by ... Entitled "Cathode Ray Tube Amusement Device", the patent describes a game in which a player controls the CRT's electron gun much like an Etch A Sketch ... By connecting a cathode ray tube to an oscilloscope and devising knobs that controlled the angle and trajectory of the light traces displayed on the oscilloscope, they were able to invent a missile game ...
Radar Display - A-scope
... voltage signal from the radar receiver on a the screen of a cathode ray tube ... a "blip" (or "pip"), an upward deflection from the abscissa on the cathode ray tube ... The cathode ray tube (CRT) was generally an electrostatic type with a circular face ...

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