katodisädeputkinäyttöjä

Katodisädeputki, known in English as a cathode ray tube (CRT), is a vacuum tube containing one or more electron guns and a phosphorescent screen. When electrons are fired from the electron gun, they strike the screen and cause it to glow, producing an image. This technology was foundational for television sets and computer monitors for much of the 20th century.

The electron beam in a CRT is typically directed and deflected by magnetic or electrostatic fields, allowing it to scan across the screen in a pattern, usually a series of horizontal lines. This scanning process, known as raster scanning, refreshes the image many times per second to create the illusion of motion. The intensity of the electron beam is modulated to control the brightness of each spot on the screen, and color CRTs use multiple electron beams and a trio of phosphors (red, green, and blue) to create a full spectrum of colors.

CRTs have largely been replaced by newer display technologies such as liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs) due to their bulkiness, power consumption, and susceptibility to image burn-in. However, their historical significance in the development of electronic displays is undeniable.