摘要 |
A shadow mask is provided in an envelope of a color cathode ray tube. The shadow mask includes a mask body having a number of electron beam apertures, and a mask frame having side walls equipped on the peripheral portion of the mask body. The side walls of the mask frame includes a pair of long side walls extending in parallel with the long axis X and a pair of short side walls extending in parallel with the short axis Y. Beads and are respectively formed on the long side walls and the short side walls. The length of each bead of the long side wall along the long axis is set in a range of 55% to 80% of the length of the long side walls along the long axis, and a width of the bead in the tube axis direction is set in a rage of 40% to 75% of the maximum width of the long side walls in the tube axis direction. The length of each bead of the short side wall along the short axis is set in a range of 55% to 80% of the length of the short side walls along the short axis, and a width of the bead in the tube axis direction is set in a rage of 40% to 75% of the maximum width of the short side walls in the tube axis direction.
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