| 摘要 |
PROBLEM TO BE SOLVED: To minimize noise magnetic field by providing a short coil, together with a deflection coil to an annular core. SOLUTION: In a uniaxial direction deflector, a deflection coil 2 is wound to the same number of windings between an upper coil and a lower coil and to change winding direction between the coils, so as to be reverse in the direction of generated magnetic flux 5. A short coil 7 is wound around an annular core 3 to link to the generated magnetic flux 5, and alternating current nozzle magnetic flux caused by a noise current component flowing through the deflection coil 2 is interrupted to stabilize deflected magnetic field 6 between a gap PQ and minimize harmful electron beam disorder. In an XY axis deflector, the deflection coil is wound in basically similarly the same as with to the uniaxial direction deflector. Deflection current 4 from a variable current source 1 generates X-axis magnetic flux 6-2 of the same magnitude in the upper and lower deflection coils and in reverse direction to each other. A stable X-axis deflected magnetic field 6-1 is thereby generated between the gap PQ, and likewise for the case of Y-axis.
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