摘要 |
PURPOSE:To improve the breakdown strength and to improve the picture quality, by performing the getter flush in the cathode ray tube then applying the high frequency discharge on the grid to eliminate the unnecessary electron generating source. CONSTITUTION:A heater 3, cathode body 4, first to third grids 5-7 and an anode body 8 are arranged in the neck section 1A of a cathode ray tube 1, and after evacuating the tube an activation process and getter flush process are performed. Then in order to prevent the production of unnecessary electron from unnecessary electron generating source provided due to the activation and the getter flush, high frequency discharge through Tesla coil device 18 is applied from the outside on the part in the neck section 1A facing with the third grid 7. Consequently the unnecessary electron generating source can be dispersed by producing the pole-less discharge ?in the tube thereby the breakdown strength can be improved easily. |