Karl Ferdinand Braun invents the Cathode-ray Tube (CRT), also known as a Braun Tube, intended for use as an oscilloscope.
While there are two fundamentally different methods of operation for a CRT, the physical principle remains the same. A cathode emits a constant stream of electrons, forming a ray, which is deflected and directed towards a screen coated with a fluorescent material. Wherever the electrons hit, the screen lights up.
In the first method of operation, rays are deflected to directly trace out the shapes that are to be displayed on screen. This is the way of CRT oscilloscopes, as well as vector displays, which have been used for a number of arcade videogames and less successful home game systems.
The other method has rays illuminating the whole screen surface by repeatedly tracing out a raster pattern, line by line. These screens are known as raster displays. The patterns to be drawn are controlled by modifying the intensity of the electron beam rather than its deflection—more electrons means a brighter dot on the screen. Raster displays also give meaning to the notion of screen resolution and refresh rate, or frame rate, commonly measured in frames per second and measuring how often this raster pattern is traced out each second. Higher frame rates reduce update delays, jerkiness of motion, and screen flicker. Colour displays have three beams separately amplified and targetting separate raster locations for each of red, green, and blue.
Up until the advent of flat-screen display technology about a hundred years later, CRT monitors were ubiquitous in television receivers and computer monitors, meaning that if computer and video games were played, they were most likely played on a CRT.
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References
- Wikipedia: Cathode ray tube
- Picture by Interiot, Wikimedia Commons (CC 3.0-by-sa)
