| 摘要 |
PURPOSE:To lighten stress concentration during a pressing process by arranging recessed holes having specific depth to plate thickness in the region between the mask effective hole part and the skirt bent part of a shadow mask in a continuity to the array of mask holes. CONSTITUTION:A shadow mask 1 of a color picture tube is devided into a mask curved part 2 and a skirt part 3 by a bent part 4. Further, the curved part 2 is devided into an effective hole part 5 and a part other than the effective hole part by an effective hole part boundary 7. Thereby, one side etching part 6 having recessed holes being about 50-90% in depth of the plate thickness is formed between the effective hole part boundary 7 and the bent part 4. In this way, stress concentration on the mask holes near the effective hole part boundary 7 during a pressing process is effectively prevented. Accordingly, color mix and multicolor collision of the picture tube are prevented by removing expansion of mask holes while extending the life of a press mold.
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