| 摘要 |
PROBLEM TO BE SOLVED: To provide a color cathode-ray tube equipped with an inline type electron gun capable of obtaining an excellent and uniform focus on the whole fluorescent screen by heavily shaping an incident electron beam shape of a post electrostatic quadrupole lens. SOLUTION: This cathode ray tube is equipped with a fluorescent screen, a shadow mask, a deflection yoke, an inline type electron gun and the like, and the inline type electron gun has a cathode 13, a control electrode 14, an accelerating electrode 15, plurally-divided focusing electrodes 16-21, and an anode 22. A first focusing voltage is added to divided focusing electrodes 16, 20, and a second focusing voltage is added to divided focusing electrodes 17, 19, 21, and a preceding electrostatic quadrupole lens, a front electrostatic quadrupole lens and a post electrostatic quadrupole lens are formed successively between the first focusing voltage-added divided focusing electrodes and the second focusing voltage-added divided focusing electrodes arranged adjacently 16-17, 19-20, 20-21. At the time of increase of the difference voltage between the first and the second focusing voltages, the preceding electrostatic quadrupole lens and the front electrostatic quadrupole lens show the function to strengthen a divergent force in the horizontal direction and to strengthen a focusing force in the vertical direction, and the post electrostatic quadrupole lens shows the function to strengthen the focusing force in the horizontal direction and to strengthen the divergent force in the vertical direction, relative to three electron beams.
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