| 摘要 |
PURPOSE:To prevent occurrence of shift caused by astigmatism on scanning picture face, by forming a plurality of thin cuttings around the outside beam pass holes in central and outside beam pass holes made through the bottom of tubular concentrating pole. CONSTITUTION:Central and a pair of outside electron beam pass holes 22-24 are made with same interval through the bottom face 21 of a concentric pole 20 formed into a bottomed tube with non-magnetic stainless steel on X-X axis corresponding with long axis of phosphor face. Thin cuttings 25 are formed in X-X direction and perpendicular direction of said outside electron beam through-holes 23, 24. A field control element made of high permeability material is arranged on the bottom of said pole 20. In other word, a pair of magnetic intensifier element discs 15, 16 are provided while holding the central electron beam through-hole 22 between them on the short axis of phosphor face or vertical axis Y-Y while shielding elements 17, 18 are arranged while surrounding the beam through-holes 23, 24 made on the horizontal axis X-X. |
