| 摘要 |
PROBLEM TO BE SOLVED: To provide an adjustment device for electrode of a CRT that adjusts high voltage through control with low voltage. SOLUTION: An anode voltage Ea boosted by a flyback transformer 2 is rectified by a diode 3, and the rectified voltage is stored in a smoothing capacitor 4 as electric charges, a voltage between an anode electrode A of a CRT 1 and ground is divided by voltage division resistors 5, 6, the divided voltage between the resistor 6 and ground is given to a focus electrode F, a miniature vacuum tube 7 which adopts a field emission array 71 is used for a current control element, a cathode current of the miniature vacuum tube 7 is changed by varying a DC gate voltage Vgk of the miniature vacuum tube 7 to a branch part of the current flowing through the voltage dividing resistor 6 to the miniature vacuum tube 7 to change the voltage across the voltage dividing resistor 6, so as to control the voltage Ef of the focusing electrode F of the CRT 1. |
