Kuvaputki

Kuvaputki, the Finnish word for cathode ray tube (CRT), refers to a vacuum tube in which beams of electrons are projected onto a fluorescent screen, creating a visible image. Developed in the late 19th century, CRT technology was the dominant display technology for televisions and computer monitors for much of the 20th century.

The fundamental principle of a kuvaputki involves an electron gun at the rear of the tube that emits a stream of electrons. These electrons are then accelerated and focused by electron lenses. A set of deflection coils, or electrostatic plates, directs the electron beam across the screen in a raster scan pattern. As the electrons strike the phosphorescent coating on the inner surface of the screen, they cause the coating to emit light, forming pixels. The intensity of the electron beam is modulated to create different shades of color and brightness.

Kuvaputki technology allowed for the creation of relatively large and high-resolution displays for its time. However, CRTs are bulky, heavy, and consume significant amounts of power. They also suffer from limitations such as flicker and geometric distortion. Over time, advancements in display technologies such as LCD, LED, and OLED have largely replaced CRTs in most consumer electronics due to their thinner profiles, lower power consumption, and superior image quality. Despite their decline in mainstream use, CRTs remain important for certain specialized applications where their unique characteristics are advantageous.