| 摘要 |
PROBLEM TO BE SOLVED: To provide a means to erase the remnant magnetizm of a yoke is erased by applying an opposite magnetic field, and which is not troublesome to switch the coil current of the electromagnetic lens, without burning the relay contact by the counter electromotive force or without noise switching noise of the relay in an electron beam device. SOLUTION: Because the remnant magnetizm of the coil to constitute the electromagnetic lens is erased, a coil for generating the magnetic field of the opposite direction is provided, the current in the opposite direction is sequentially made to flow in the coil and in the coil for the electromagnetic lens, and this is constituted so that the remnant magnetizm remaining in the iron core of the magnetic pole is erased by sequentially making it change so that its generating magnetism may be gradually decreased. COPYRIGHT: (C)2004,JPO
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