In older video cameras, before the mid to late 1980s, a video camera tube or pickup tube was used instead of a charge-coupled device (CCD) for converting a video image into an electrical signal. Several types were in use from the 1930s to the 1980s. These tubes are a type of cathode ray tube or "CRT". Any vacuum tube which operates using a focused beam of electrons ("cathode rays") is known as a cathode ray tube. However, in the popular "CRT" usually refers to the "picture tube" in a television… (More on Vidicon)