Tension mask cathode ray tube

摘要

A tension mask cathode ray tube has a vacuum tube and an inner shield mounted within the vacuum tube to shield the vacuum tube from geomagnetism. A value Br/Hc of the inner shield where Br indicates a residual magnetic flux density and Hc indicates a coercive force is established to be 1.0-2.0 times more than a value Br/Hc of the mask frame. In this structure, the route of electron beams is established to be more precise. Consequently, the purity characteristic and the convergence characteristic are improved while forming a precise raster. In this way, the display screen quality can be enhanced.