Abstract: A transmission electron microscope for irradiating a specimen with an electron beam, wherein the electron beam passed through the specimen is imaged on an imaging screen by a magnifying lens system. The electron microscope includes a deflector for deflecting the electron beam to thereby scan a specimen with the electron beam, and a memory for storing a range within which the specimen is to be preliminarily scanned with the electron beams and the number of scans to be performed. The specimen is preliminarily scanned with the electron beam within the preliminary scan range for the number of times on the basis of the corresponding data read out from the memory.

Abstract: A viewing system destined to be employed in association with a transmission electron microscope, which system comprises a converter for converting an image of a specimen focused by a focusing lens system of the electron microscope into an electric signal, a frame memory for processing the electric signal obtained from the converter for each image frame to thereby derive image frame data to be stored therein, a display unit for displaying an electron-microscopic image with or without other data on the basis of the contents of the frame memory, a simulator for deriving a simulated image corresponding to the electron microscopic image, a simulation frame memory for processing the simulated image data derived through the simulated image deriving unit for each image frame to thereby store data resulting from the processing and displaying a simulated image on the basis of the output of the simulation frame memory, wherein the conditions required for deriving the simulated image are transmitted from the unit for con

Abstract: An electron microscope comprising an electron gun for generating an electron beam, an electron lens system for irradiating a specimen with the electron beam, an electron lens system for magnifying an electronic image transmitted through the specimen, a fluorescent plate arranged removably in the path of the magnified electron image for converting the magnified transmitted electron image into a visual image, a viewing window for observing the visual image, a CRT display unit for displaying data related to the transmitted electron image, which is arranged at a position where the data is visible from the viewing window, and an optical system for projecting the data on a photo-sensitive material which is exposed to the transmitted electron image.

Abstract: An electron beam emitted from an electron beam source is applied to a sample and when it produces an magnified image of the sample on a fluorescent plate, the amount of the electron beam is detected. When the accumulation of the electron beam radiation reaches a predetermined value with lapse of the time, the beam density on the surface of the sample is so controlled as to be reduced to zero or below a certain preset level, whereby the sample is prevented from damage due to excessive exposure to the electron beam.

Abstract: A condenses lens system condenses an elctron beam onto a specimen. The electron beam thus transmitted through the specimen is magnified by a magnifying lens system. The magnified electron beam is projected onto a fluorescent screen, and the image of the specimen is visually observed. The quantity of electrons per unit area in the magnified electron beam is detected by an electron beam detector. In response to the detected signal, the condenser lens system is controlled so as to make constant the quantity of electrons per unit area in the magnified electron beam.