An improved CLEAR gun for 19" high resolution CDT

Abstract

An electron gun for high resolution 19" Cathode-ray Display Tube (CDT) has been developed, by using an improved "CLEAR" gun design. To avoid cut off uniformity and the cathode loading problem, we choose to maintain the 0.4 mm G1 aperture diameter. For the higher resolution requirement, the depth of the common lens and the object distance were increased. The former will enlarge the equivalence main lens diameter and spherical aberration was reduced. The latter will cause larger object distance, i.e., smaller magnification. According to the modeling results, the spot size of the new gun is 25.8% better in horizontal direction and 8.6% in vertical direction than our conventional "CLEAR" gun.