| 摘要 |
PURPOSE:To produce a high-speed pulse beam stably without causing any shift of the central axis by synchronously supplying pulse voltages, which have different polarities and an equal absolute value of amplitudes, to a pair of deflection electrode plates used for pulse-beam generation. CONSTITUTION:In turning on a beam, since a voltage of 0V is supplied to both of deflection electrode plates 11 and 12, the beam travels straight forward without undergoing any deflection, and a pulse beam having a pulse width corresponding to the duration of the 0V pulse is obtained. When the beam is held on, in the output stage indicated by the figure, since a pulse voltage having a voltage amplitude half that of the conventional pulse voltage is handled, the signal response time can be made sufficiently short compared to the conventional signal response time. As a result, a pulse width obtained when offset voltage develops in the 0V pulse voltage becomes shorter than the conventional pulse width. Consequently, a high-speed pulse beam can be produced stably without causing any shift of its central axis. |
