Apparatus for maintaining tension in a shadow mask

摘要

An apparatus for maintaining tension in a mask frame of a cathode ray tube. The apparatus includes affixing a shadow mask to a pair of triboxes disposed along opposite sides of a mask frame at a predetermined tension. The triboxes are coupled to the mask frame by braces having a different coefficient of thermal expansion than the triboxes so as to compensate for the expansion of the frame during thermal cycling of the cathode ray tube. Consequently, it is possible to maintain the tension force applied to the shadow mask by the mask frame.