| 摘要 |
PURPOSE:To eliminate a need for high accuracy as to assembling of electrodes with respect to vertical direction by dividing a vertical deflecting position of an electron beam into several sets of blocks and increasing the deflection interval among the blocks more than the deflection interval in a block thereby making the variance in the beam deflection position unremarkable. CONSTITUTION:The beam deflection position is divided, e.g., into 8 blocks a vertical deflection data in a memory in a vertical deflection drive circuit is changed to narrower the interval of electron beams (black round mark) in a block than the deflection interval of the electron beam (white round mark) by a conventional deflection means and increase the deflection interval among the blocks than that of the conventional means. The deflection interval is L0 in the conventional vertical deflection, while the deflection method as above (biasing method) gives an deflection interval of L1, because the interval is recognized as the interval of the deflection position as a set.
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