| 摘要 |
PURPOSE:To prevent permanent deformation of a mask frame when being heated and the deterioration of color purity by making non-liner the displacement of a thermal expansion correcting plate made of a bimetal. CONSTITUTION:A shadow mask 23, its supporting frame 22, a thermal expansion correcting plate 21 fixed to the frame at its one end, at its other end, fixed to a holder 27 having a hook part 26 fitted with a panel pin 25 installed onto the inner surface of a side wall 241 of a panel 24 are constructed in a color picture tube. The thermal expansion correcting plate 21 consists of a bimetal and its deformation amount to temperature change has a non-linear characteristic. For example, the amount of its displacement up to about 200 deg.C from zero increases gradually, and decreases above 200 deg.C. This bimetal is manufactured by a combination of 36% Ni alloy and 42% Ni alloy, or the like. Thus, the parmanent deformation of a frame can be prevented and an exellent color purity can be obtained. |
