| 摘要 |
PURPOSE:To simplify the manufacturing process and to enable provision of an electron gun of high quality in a short period of time, by producing a thick plate member with holes by application of punching in the same direction to form the periphery of the member and the holes, i.e., those for the electron beams to pass through. CONSTITUTION:In producing a thick plate member with holes 17d, 18a, first, the member without holes is punched out from a material of predetermined thickness applying the punching in the direction as shown by the arrow 311, 312, namely in the direction away from the main lens. Then, the hole portions 11 for the electron beams to pass through are punched by application of the punching in the same diretion as indicated by the arrow 32, i.e., away from the main lens, with the surface 33 not including the portion where burr 33a is formed by the above first punching taken as the base surface. Thus, the burr 33a produced at the punching of the periphery and the burr 33b produced at the punching of the holes 11 for the electron beams to pass through are adapted to be on the same end, the end to be supported by a dish shaped member with holes in the succeeding process, and because of it, there are formed curved surfaces 34a, 34b of the substantially same curvature on the end to face the main lens. Then, by substantially removing the burrs 33a and 33b by a short period of time of tumbling, the 5th electrode comprising 17b, 17c, and 17d and the 6th electrode comprising 18a and 18b can be provided. |
