| 摘要 |
PURPOSE:To correct vertical distortion by decreasing the absolute value of a vertical deflecting current from the center of a screen upward and downward with large sensitivity according to the extent of a drop of the high voltage of a high voltage generating circuit. CONSTITUTION:The vertical deflecting current (d) to flow a vertical deflecting coil 20 is generated by a vertical oscillating circuit and amplified by a vertical exciting circuit 18 and a vertical deflection output circuit 19. The gain of the vertical exciting circuit 18 is controlled by a negative feedback circuit NL and a control circuit 46. When an image having larger brightness than the background appears in the screen vertically, the high voltage (b) of the high voltage generating circuit drops where the image is present. The collector-emitter impedance values of transistors (TR) 37 and 38 of the control circuit 46 increases at said image position to control the gain of the vertical exciting circuit 18. Then, no vertical distortion is generated even if vertical deflection sensitivity increases according to the drop in the high voltage (b). |
