A COLOUR CATHODE RAY TUBE

摘要

A shadow mask (5) for a colour cathode ray tube has a layer (53) bonded to a major surface (51). The layer is made of a ceramic material, such as a lead borate glass, and is thermally bonded to the shadow mask (5) at a temperature which is at least as high as the normal operating temperature of the shadow mask. When the mask cools to room temperature, the ceramic layer prevents full thermal contraction and the mask retains residual tensile stress which reduces expansion of the mask on subsequent rise of temperature.