| 摘要 |
PURPOSE:To perform accurate track adjustment of an electron beam by providing two pairs of two-divided coil groups, which generate a magnetic field in accordance with applied voltage, on a neck part of surrounding a passage of the electron beam, so that each magnetic field is almost orthogonal, and adjusting applied voltage and polarity in each pair. CONSTITUTION:Two pairs of two-divided coil groups L1, L1' and L2, L2' are provided so that magnetic field direction by each pair can be almost orthogonal, on a neck part 2 of surrounding a passage of an electron beam 4. In an intermediate point position of a potentiometer, applied voltages of the first and second coils L1, L1' and L2, L2' are set each to zero so that no magnetic field is generated in each coil. Next, when a position of the potentiometer is adjusted, a resultant field of the generated magnetic field is changed to change a track of the electron beam. In this way, an adjusted condition is accurately held, and automatic adjustment is made possible. |
