| 摘要 |
PURPOSE:To improve the rate of maintaining light flux by a method wherein inner tubes made of glass are arranged between a pair of electrodes provided inside an outer tube made of glass while thin films made of alminium oxide are formed on the surfaces of the inner tubes to form bent discharge routes. CONSTITUTION:Electrodes 41 and 42 are provided inside an outer tube 1 made of glass forming a discharge space. Inner tubes 51 and 52 made of bent glass, whose one side ends airtightly contain the electrodes 41 and 42 while the other ends are open inside the outer tube 1, are arranged between the electrodes 41 and 42. Thin films 7 of alminium oxide are formed on the inner-and-outer surfaces of the inner tubes 51 and 52. Further, the thin films 7 formed on the inner surfaces of the inner tubes 51 and 52 are coated with phosphor layers 6. Consequently, the thin films of alminium oxide prevent natrium precipitating from glass and mercury inside the tubes from combining with each other thus to improve the rate of maintaining light flux. |
