CRTtechnologie

CRT technology refers to cathode-ray tubes, a vacuum-tube platform that was the dominant display technology for television sets, computer monitors, and many oscilloscopes from the mid-20th century until the early 2000s. A CRT contains a sealed glass envelope with an electron gun that emits a stream of electrons, a vacuum, a phosphor-coated screen, and a deflection system to steer the beam across the screen in a raster pattern.

In color CRTs, three electron guns or a single gun with a shadow mask or aperture grille direct red, green, and blue beams to corresponding phosphor elements, producing full-color images. Convergence and purity adjustments ensure accurate alignment of the colors. The tube relies on phosphor persistence to control how long the image remains visible after the beam passes, and the image is refreshed many times per second.

The screen emits light when struck by electrons; brightness, color accuracy, and resolution depend on the quality of the phosphors, the precision of the electron optics, and the deflection system. CRTs deliver fast response, wide viewing angles, and deep blacks, but they are heavy and bulky, consume substantial power, and can suffer from geometric distortion, magnetic interference, and burn-in under certain conditions.

With the rise of flat-panel technologies such as LCD, LED, and OLED, CRT technology was largely phased out in consumer devices, though it remains in use for certain professional displays and specialized equipment, including oscilloscopes and some medical imaging devices. Maintenance considerations include degaussing, tube aging, and phosphor degradation. Despite obsolescence in most markets, CRT technology remains a notable milestone in the history of electronic displays.