205150 ⎘
Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored; Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output having grid-like image screen through which the electron ray or beam passes and by which the ray or beam is influenced before striking the luminescent output screen, i.e. having "triode action"