| 摘要 |
A display tube of the kind in which a line-scanned, low-energy electron beam (32) is directed into a space between a planar array of elongate deflection electrodes (42) and the input side of a laminated dynode channel electron multiplier (44). The deflection electrodes are switched sequentially by driving means between two potential levels (V1, V2) so as to deflect and scan the incoming beam frame-wise over the multiplier input, the current-multiplied beam emanating from the multiplier being directed onto a screen (16) to produce a display. By ensuring that the beam acceleration voltage, Va, satisfies the relationship 1.3 Vs<Va<2 Vs, where Vs=V2-V1, beam spot size at the multiplier input is maintained and Moirée patterning effects in the display are effectively suppressed. The multiplier input electrode and final anode of the electron gun are advantageously held at the higher (V2) of the switched potentials.
|
