| 摘要 |
In order to prevent the walls of the envelope (10) of a flat panel display tube having a large area screen from imploding, supporting walls (22) are provided to divide the interior of the envelope into a plurality of modules. Each module has its own electron beam generating means (24) for producing a low voltage, low current, intensity modulated electron beam (26) which is directed vertically upwards. A laminated channel plate electron multiplier (28) is disposed across the module and extends substantially parallel to the front and rear walls (12, 14) of the envelope. A single column of channels in the electron multiplier (28) is illustrated. The spacing of the channels determines the vertical resolution of the image produced. In order to deflect the electron beam (26) into a particular channel, a plurality of deflector electrodes (30) are disposed on the rear wall (14). These electrodes (30) and the input dynode of the electron multiplier (28) are generally held at the same potential to define a field-free space. However, in order to deflect the electron beam (26), the potential applied to electrodes (30) ahead of the deflection point is reduced so that the beam is deflected towards the selected channel in the electron multiplier (28). The current-multiplied electron beam from the output of the electron multiplier (28) undergoes focusing, horizontal deflection and post deflection acceleration as a result of suitable voltages applied to electrodes provided on the supporting walls (22). These electrodes may be parallel to each other or may diverge in a direction towards the front wall (12).
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