公开(公告)号：US3624393A

公开(公告)日：1971-11-30

申请号：US3624393D

申请日：1970-07-13

Applicant: SOPELEM

Inventor： TORQUEBIAU EMILE

IPC: H01J37/26 ,  G01Q20/02 ,  G01Q30/02 ,  H01J37/05 ,  H01J37/12 ,  H01J37/14

CPC classification number: H01J37/05

Abstract: In an electron microscope having a velocity filtering system involving reflection in a prism, the normal objective lens is replaced by a complex lens comprising three electrostatic lens elements. This arrangement enables the order of image and diffraction diagram in the propagation path to be reversed, so that the diffraction diagram can be filtered as well as the image.