| 摘要 |
PURPOSE:To enable the accurate irradiation of an electron beam on an analyzing point (a point to be analyzed) chosen beforehand by a specimen image and thereby to enable the expected analysis, by supplying a signal, which is multiplication of a horizontal scanning signal and vertical scanning signal level-adjusted, to a deflecting means. CONSTITUTION:A vertical scanning signal from a vertical scanning signal generating circuit 9 is added to a signal from a vertical level adjusting circuit 12 in an adding circuit (adder) 11, the resulting signal being supplied to a multiplying circuit (multiplier) 10 and multiplied by a horizontal scanning signal from a horizontal scanning signal generating circuit 8 in the circuit 10. The output signal from the circuit 10 is added to a signal from a horizontal level adjusting circuit 14 in an adding circuit (adder) 13 and the resulting signal is supplied to deflecting coils 4 and deflecting coils 19 for a cathode ray tube 7. The circuit 12 and 14 are adjusted appropriately so that the scanning signals at the expected portion of a specimen 3 may become zero and the signals from the circuits 12 and 14 are supplied respectively to the deflecting coils 4 and 5 by switching over switches 15 and 17. Thus, it is possible to irradiate the chosen portion of the specimen 3 continuously with the electron beam and to obtain the expected analysis result.
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