Abstract: An improved resolution electron gun for a cathode ray tube(CRT) is provided having a cathode, a control grid and an anode. A positive voltage is applied to the anode for the purpose of drawing the electron beam from the cathod, which emits the electron beam along its principal axis. The control grid between the cathode and the anode has a modulating drive voltage to modulate the emitted beam. The anode and the grid are aligned along the principal axis of the cathode and are adjacent to one another. A limiting aperture is mounted along the principal axis to clip the beam and reduce its diameter. A screen is provided along the principal axis within the CRT to receive the projected beam. To obtain increased resolution, the modulating drive voltage is increased while the aperture size is decreased. More specifically, the modulating drive voltage is increased beyond 25% of a predetermined maximum cutoff value, and the limiting aperture permits less than 50% of beam current to transmit.

Abstract: An image intensifier tube having an output imaging screen comprising a scintillator layer of juxtaposed crystalline rods made of doped alkali-halide material, such as cesium iodide doped with sodium or thallium, for example.