| 摘要 |
PURPOSE:To obtain a more efficient and compact fluorescent lamp by making an outer tube shape almost spherical and by making the mercury vapor pressure approach most suitable value by lowering the coolest tube wall temperature. CONSTITUTION:A plurality of bent internal tubes 3, 3' are arranged in series through a spacer 4 within an air-tight space formed by an outer tube 1 and a stem 2, at least one portion of the mutual connecting part of the internal tubes 3, 3' is opened to the air-tight space, while electrodes are provided at both ends of the internal tubes 3, 3' arranged in series and thus the internal tube 3, 3' are formed in a discharge passage. The shape of the outer tube 1 of such a fluorescent lamp is made almost spherical. Accordingly, the coolest tube wall temperature can be made to approach the most suitable value without losing compactness, and a fluorescent lamp of highly efficient and a compact shape can be obtained. In this lamp, the point indicating the coolest tube wall temperature is formed at the tube wall of the outer tube 1 farthest apart from the internal tube 3, as shown by ''P'' point in the drawing. |
