katodstrålerörens

Katodstrålerör, often abbreviated as CRT from its English equivalent Cathode Ray Tube, is a vacuum tube containing one or more electron guns and a fluorescent screen. When an electric current passes through the electron gun, it generates a beam of electrons. This beam is then accelerated and focused by electromagnetic fields.

The focused electron beam strikes the inside of the screen, which is coated with phosphors. These phosphors emit light when struck by the electrons, creating a visible image. By rapidly scanning the electron beam across the screen in a pattern, typically a raster scan, and modulating its intensity, a complete image can be displayed.

CRTs were the dominant display technology for televisions and computer monitors from the mid-20th century until the early 21st century. Their advantages included good color reproduction and relatively low manufacturing costs. However, they were bulky, heavy, and consumed significant power. Furthermore, they were susceptible to issues like screen burn-in and image distortion.

The development of flat-panel display technologies, such as liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs), has largely replaced CRTs in modern electronics due to their thinner profiles, lower power consumption, and improved resolution and refresh rates. While CRTs are now uncommon in consumer products, they remain important in some specialized scientific and medical imaging applications where their unique characteristics are still valued.