摘要 |
An electron source section including a first detecting sub-section and a first control sub-section and an image formation section including a second detecting sub-section and a second control sub-section are arranged in series. The first detecting sub-section detects at least one of the shape, diameter, brightness and spatial position of a crossover image formed by the electron source section to become an electron source of the image formation section and the direction of emission of the electron beam emitted from such crossover image, thereby to control the first control sub-section. The second detecting sub-section detects at least one of the shape and size of an electron beam image formed on a subject to be irradiated by the beam, and the current of the electron beam forming the electron beam image, thereby to control the second control sub-section.
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