CATHODE RAY TUBE WITH IMPROVED ELASTIC MODULUS AND STRENGTH OF SHADOW MASK BY IMPROVING SHAPE OF CROSS SECTION OF ELECTRON BEAM PASSING HOLE OF SHADOW MASK

摘要

PURPOSE: A cathode ray tube is provided to improve an elastic modulus and strength of a shadow mask by improving the shape of the cross section of the electron beam passing hole of the shadow mask. CONSTITUTION: A cathode ray tube comprises a funnel serving as a rear glass; a panel coupled to the funnel, wherein the panel has an inner surface on which a phosphor screen is formed; an electron gun for emitting electron beams; a deflection yoke for deflecting electron beams in a vertical or horizontal direction; a shadow mask(5) for selecting colors of electron beams; and a mask frame where the shadow mask is coupled. The shadow mask has a plurality of electron beam passing holes. Each of the electron beam passing holes has a larger opening part(51) and a smaller opening part(52). A formula 0.23<=t/T<=0.5 is satisfied, wherein T is the total thickness of the shadow mask, and t is the thickness measured from the smaller opening part side to the portion where the smaller opening part and the larger opening part contact with each other.