| 摘要 |
PURPOSE:To obtain a solid Y-axis modulation scanning picture by adding a simple blanking generation circuit to a conventional device. CONSTITUTION:An electron beam 2 is irradiated on a sample 4 and its secondary electron is detected by a detector 5. The electron is input to an addition circuit 14 through a change-over switch, added to a vertical scanning signal 13, and then applied to the vertical deflection coil 11Y of a cathode-ray tube 9, while at the same time, direct power 19 is applied to a brightness modulation grid 10. The output of a blanking generation circuit 20 consisting of a number of delay elements and comparator circuits is added to the signal of a blanking circuit 17 and applied to a blanking grid 18. As a result, a solid sense can be applied to the YMI observation and its observation can be facilitated by comparing the intensity of the image signal which can be obtained every horizontal scanning with that of the previously obtained image signal and applying the blanking signal to the CRT 9 thereupon. |
