| 摘要 |
PURPOSE:To improve both brightness and resolving power of a tube, by forming a prismatic crystal, used as a fluorescent material, into a mutually independent finely collective unit with the method in which a speed of evaporation deposition for the fluorescent material is changed on the half way of its process. CONSTITUTION:A base plate 11 is heated to 200 deg.C by a heater 21, and then a boat 15, in which an evaporated material 13 is contained, is heated at low temperature by a heater 23. Said evaporation method forms a crystal unit with diameter 100mu- 200mu and thickness 5mu-20mu. Then it is gradually cooled and a boat 17, in which the evaporated material 13 is contained, is heated at high temperature by a heater 25. In this way, a prismatic crystal in diameter 5mu-20mu and thickness 80mu-100mu is constructed. Further with a gradual cooling, then a boat 19 in which the evaporated material 13 is contained is heated at high temperature by a heater 27. This results in the construction of a fluorescent material layer in diameter about 5mu-20mu and thickness about 10mu. The above process is successively followed by a vacuum baking operation. |
