| 摘要 |
PROBLEM TO BE SOLVED: To decrease the anode-grid pulse current, and ensure an aging treatment of plural fluorescent character display tubes, with a small power supply. SOLUTION: Each of plural fluorescent character display tubes 1 is constructed of an anode 15 having a phosphor formed into a prescribed patterned shape, a cathode 17 which emits electrons, and a grid 16 which is disposed between the anode 15 and the cathode 17 and accelerates or interrupts the electrons emitted from the cathode 17. These electrodes 15, 16, 17 are accommodated in a vacuum outer enclosing receptacle. A pulse scanning circuit 22 successively scans plural fluorescent character display tubes 1 one by one and successively applies a pulse voltage for driving on the anode 15 and the grid 16 under a such condition that a drive voltage is applied to each of the cathodes 17 of the plural fluorescent character display tubes 1 from an alternating current power supply 24 via a driving transformer 23 so as to emit electrons.
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