| 摘要 |
PURPOSE:To obtain an electron gun electrode structure having a large diameter lens aperture for emitting electron beams with small astigmatism by forming a gap tween a central portion in the direction of an aperture array and both side apertures, and a gap tween both outside apertures and a cylinder outside such that they are depressed into a concave shape from a closed surface including said bored apertures therein. CONSTITUTION:An electrode structure 2 and an electrode structure 2' having the same structure as the former are disposed facing to each other on the same axes 20R, 29G, 20B. A primary electron lens is formed in a cross section including the axes 20R, 29G, 20B by applying high tension to the structure 2 and a prescribed low tension to the structure 2'. For the structure 2, electron beam transmitting holes 21R, 21G, 21B located on gun axes 20R, 20G, 20B having a distance S among apertures equal to each other are bored in a closed surface 22, and a cylinder side part 23 is formed adjoining to the closed surface 22. Periphery of each aperture is surrounded by a projecting edge 24 projecting into the electrode, and gap portions 25A between the apertures 21R, 21G and between the 21G, 21B and gap portions 25B between one of the cylinder side portions 23 and the aperture 21R and between the other of the cylinder side portions 23 and the aperture 21B project into the electrode by a height d with the same width lfrom the closed surface 22, and an aperture array line is depressed into a concave shape. |
