| 摘要 |
PURPOSE:To improve the ball piece sensibility thus to improve the convergence regulating function by making cuts for splitting the annular face section of shield cup along the circumferential direction. CONSTITUTION:A shield cup assembly is contained in the neck tube wall 7 to flow correction current to the convergence yoke coil 9 wound over the convergence yoke core 8 to magnetize the ball piece 6 through said core 8 and wall 7. Here, the eddy current loss occurring in the shield cup 5 is reduced thus to reduce the magnetic resistance against the magnetic flux 10 passing through the ball piece 6. The ball piece 6 is prevented from contacting against the annular face of shield cup 5 to further reduce the magnetic resistance against the magnetic flux passing through the ball piece 6 thus to improve the sensibility of ball piece 6 and to function effectively onto the electron beam 12 passing through the beam pass holes 11 at the opposite sides. Consequently, convergence regulating function is improved resulting in simplification of convergence correcting circuit. |
