SHADOW MASK, CATHODE-RAY TUBE, AND SHADOW MASK MOLDING METHOD AND DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a shadow mask, capable of preventing lowering of an yield in process by making the strength of the curved surface improved. SOLUTION: A waveform bead 42, having a gentle curve is formed on the peripheral edge of a rectangular shadow mask face 41a. The bead 42 is set to have a larger space from the outside at a longitudinal middle portion than the space from the outsides at other portions. The strength of the curved surface of the shadow mask 41 is improved and the productivity thereon is improved, which results in a high accuracy cathode-ray tube.