| 摘要 |
PURPOSE:To obtain a distribution image of an electron ray emission angle of high picture quality without using an expensive detector anew and with a very small number of electron rays cut in a focusing lens. CONSTITUTION:Firstly a switch 11 is connected to the side of deflecting coils 16a and 16b. Thereby a scanning signal is supplied only to the deflecting coils 16a and 16b so that electron rays, allowed to pass through the first focusing lens 8 and further finely focused by an object glass 13 are two-dimensionally scanned on a sample 14. The secondary electrons, for instance, which are generated from each part of the sample through said scanning, are detected by a detector 17 and the output thereof is supplied to a cathode tube 19 so that a sample image is displayed on said cathode tube. On the other hand, when the emission angle distribution of electrons from an electron gun is required to be meassured, said switch 11 is switched over to the side of a deflecting coil 10. Thereby the electrons emitted from the electron gun 1 at the angle shown by a dotted line are deflected as illustrated and as a result therefrom, an angle distribution image of the electron emission is obtained on the cathode ray tube. |
