| 摘要 |
PURPOSE:To measure an optional part of a two-dimensional picture with excellent contrast by operating an output of an incident electron ray incident position detector to calculate the incident position and obtaining the number of times of incident at each position to display the result on a TV monitor as the timewise separable two-dimension state. CONSTITUTION:An optical image is formed to a photoelectric plane 7 formed at the inside of an air-tight package 4 through a lens 6. The electron ray incident position detector 8 is provided in opposition to the plane 7, an electric field is generated from the electron ray irradiated from the plane 7 through a mesh electrode 9 and a cylindrical electrode 10, the magnification of the image is changed by focusing coils 11, 12, and the position of the image is changed by a drive voltage applied to deflection electrode pairs. Then the output of the detector 8 is subject to arithmetic by an incident position arithmetic circuit 21 to calculate the incident position thereby obtaining the number of times of incident at each position. The output is fed to a secondary counter 22 via a gate circuit 24, from which the result is displayed on the TV monitor 23 while the interval of the incident electrons is brought into the two-dimension state so as to be separated timewise. |
