| 摘要 |
PURPOSE:To maintain the flatness of a cover glass for a display tube, and enhance its reliability by placing a glass plate and glass pieces over a mold, heating and fusing the glass pieces locally to the periphery of the glass plate, and forming a side wall part by heat molding. CONSTITUTION:A die 9 is provided with a groove Q in which glass pieces 10, 10', 10'' and the like are placed. Part of the die 9 which touches the inner sides of the pieces 10, 10' and 10'' is provided with a taper in order that release of the product is facilitated. The glass pieces 10-10'' are combined and inserted into the groove Q of the die 9. After the glass pieces 10-10'' are placed in such a way, a glass plate 1 and a male die 11 are placed over the pieces 10-10'' in that order, and the male and female die 9 and 11 are subjected to high-frequency dielectric heating by using N2 as the protection gas for the die 9. Since the above dielectric heating primarily raises the temperature of only the graphite die, the appearance of a glass plate 1 corresponding to a display screen is not deteriorated in its flatness. Here, the male die 11 moves down as its temperature rises, and the glass pieces 10, 10' and 10'' are fused to each other owing to downward pressure and extension developed due to their temperature rises. |
