| 摘要 |
PURPOSE:To reduce the quantity of wrong landing, by performing baking so that a glass layer with a smaller coefficient of expansion than the material of a shadow mask is provided on the electron-gun-side main surface of the shadow mask, and by combining a panel with a mask to provide a fluorescent surface. CONSTITUTION:A shadow mask material having numerous through holes 51 along a main surface 50 is press-formed so as to extend along the form of the inside surface of the panel of a color picture tube. At that time, the shadow mask material is provided with a peripheral flange 8 for securing the material to a frame 7. Baking is then performed so that a glass layer 52 made of a lead borate glass or the like and having a smaller coefficient of expansion than the mask material is provided on the electron-gun-side main surface of the material. A panel and a mask are thereafter combined with each other to provide a fluorescent surface on the inside of the panel. According to this constitution, even if the mask is deformed due to the baking, the wrong landing of an electron beam on the panel is reduced. |
