| 摘要 |
<p>PURPOSE:To enable many electron emission elements to be easily controlled with high precision, by changing driving voltages applied to the electron emission elements whenever pulses of input pulse signals are inputted by a driving means. CONSTITUTION:When a pulse signal phi is inputted to an input terminal T in a logic circuit 13, the output terminal Q is inverted to be on a high level and on a low level alternately whenever the pulses are inputted. When the output terminal Q is on the high level, an electronic switch 12 is turned ON, so that a current flows across a resistance R and a voltage approximately equal to a voltage V2 is applied to an acceleration electrode 11. When the voltage much higher than that on the electrode (a) is applied to the acceleration electrode 11 in this way, electrons are accelerated and emitted from an electron emission port of an electron emission element 10. On the contrary, when the output terminal Q is on the low level, the electronic switch is turned OFF, so that the acceleration electrode 11 becomes equipotential with the electrode (a) and the electron emission is suppressed. Therefore, the electron emission can be performed at desirable timing or for a desirable time only by properly setting periods and phases of the input signal phi.</p> |
