| 摘要 |
PURPOSE:To relieve the right deviation of green in a screen by partially changing the thickness of a final accelerating electrode or the like in an electron gun to make the phases of a horizontal deflection magnetic field applied to a center beam and both side beams different. CONSTITUTION:The electron gun of an in-line type color picture tube is formed by providing a magnetic field control element 7 consisting of a material with high permeability in the neighborhood of electron beam ejecting holes 6B, 6G, 6R of the electron gun to eliminate the coma aberration of a deflection magnetic field. And a convergence cup 12 which is a final accelerating electrode is formed to make the portion 12A through which magnetic flux passes in the neighborhood of a center beam passing hole 6G thicker than the portion 12B through which magnetic flux passes in the neighborhood of side beams 6B, 6R. And by the action of eddy current the phase of a horizontal deflection magnetic field 2 acting on the center beam passing hole 6G is advanced than that of the horizontal deflection magnetic acting on the side beams 6B, 6R. Accordingly, it is possible to reduce the right deviation of a green beam to improve the picture quality. |
