| 摘要 |
PURPOSE:To easily obtain a fluorescent lamp of a low cost by forming a phosphor film on the inner wall of a glass tube, and spraying a suspension of a micro borate powder of an alkaline earth metal on the phosphor film so as to form a thin layer made of a borate on the film. CONSTITUTION:A phosphor suspension principally containing a phosphor powder, polyethylene oxide and water is applied to the inner wall of a glass tube, thereby a fluorescent film being formed. A liquid prepared by suspending barium borate in ethyl alcohol is sprayed on the surface of the fluorescent film to form a barium borate layer on the surface. By doing above, the trouble of forming two layers by applying two chemical liquids can be saved. Consequently, a fluorescent lamp having a layer made of a borate of an alkaline earth metal over its phosphor film can be obtained at a reduced cost. |
