| 摘要 |
PURPOSE: An extended shadow mask and its supporting frame is provided that would not be affected by a local overheating, has an appropriate natural frequency of vibration and can efficiently with stand a sealing operation of a cathode-ray tube at a high temperature. CONSTITUTION: The masking device for a color cathode-ray display tube has formats of a flat screen, a supporting frame (3) for an extended shadow mask (2) and the extended shadow mask (2) that is attached to the supporting frame (3) so as to be bearable to extension in room temperature. In the device, the supporting frame (3) is made from a cured Fe-Ni alloy which has a thermal expansion coefficient of not more than 5x 10-6K-1 within 20-150deg.C and has a yield stress Rp0.2 of not less than 700 MPa at 20deg.C, and the extended shadow mask 2 is made from a cured FeNi or an Fe-Ni alloy which have a thermal expansion coefficient of not more than 5x10-6K-1 within 20-150deg.C. |
