| 摘要 |
PURPOSE:To reduce the wastage of deflection in an electron beam, by restricting one side of a deflecting current to a fixed value when the deflecting current of either side of an X deflecting circuit or a Y deflecting circuit in an electron beam deflecting device goes beyond the specified value. CONSTITUTION:Each output of potentiometers 3 and 6 to set a deflecting angle in an electron beam connected to a reference power source Es is given to an X deflecting coil 2 and a Y deflecting coil 5 respectively via an X deflecting circuit 1 and a Y deflecting circuit 4. In addition, a voltage source Es/1.4 is installed, giving voltage to comparators 7 and 9 via diodes D1 and D2 and comparing the voltage with that of each of potentiometers 3 and 6, thus the opening or closing of each of switches 8 and 10 connected to deflecting circuits 1 and 4 is controlled. Therefore, when one side of deflecting currents in both X and Y directions goes beyond the Es/1.4, another side of the deflecting circuit is limited whereby the wastage of deflection in an electron beam can be reduced and the capacity of a circuit element and a power source can be thus reduced. |
