| 摘要 |
<p>PURPOSE:To nearly unify the operating temperature of three substrate metals and suppress the change of the color tone during operation by gradually increasing the heat quantity or heating efficiency of a thin film ribbon-shaped heating element deposited on a heat-resistant insulated substrate in zigzags toward both sides from the center section. CONSTITUTION:A thin film ribbon-shaped zigzag heating element made of tungsten is deposited and formed on a heat-resistant insulated substrate 1 to heater terminals on both sides. The heat quantity or heating efficiency of the heating element is gradually increased toward both sides from the center section, the heat quantity on both sides is increased, the temperature of a substrate metal at the center can be made nearly equal to the temperature of substrate metals at both sides. The temperature of three substrate metals is unified, the electron emission characteristic is stabilized over a long period, the change of the color tone during operation can be suppressed.</p> |
