Orthicons

Orthicons are a type of camera tube used in early electronic television systems. They function by converting an optical image into an electrical signal. The core of the orthicon tube is a target plate, typically made of a photoconductive material like antimony trisulfide. When light strikes the target, its electrical resistance changes. A scanning electron beam, generated by an electron gun, sweeps across the back of the target plate. Where the light is brighter, the resistance of the photoconductor is lower, allowing more charge to flow from the target to the electron beam. This variation in charge flow is then amplified and processed to create the video signal. Orthicons were a significant development in television technology, offering improved picture quality over earlier camera tubes like the iconoscope. They were widely used in broadcasting and early video recording applications. However, orthicons were eventually superseded by more advanced technologies such as vidicon tubes and later, solid-state image sensors like CCDs and CMOS sensors, which offered greater sensitivity, resolution, and reliability.