| 摘要 |
PURPOSE:To eliminate an useless positive column lengthy part for improving photo-output by a method wherein two U-shaped inner tubes airtightly containing an electrode at one end respectively are provided inside of an outer tube while open end sides thereof are bent to make open ends to face closely each other. CONSTITUTION:Electrodes 31 and 32 are sealed to a substrate 2 of an outer tube 1, U-shaped inner tubes 41 and 42 which enclose said electrodes 31 and 32 and whose inner walls are applied with a phosphor 8, are provided and open end sides thereof are bent while arranging so that open ends 41c and 42c may face most closely. And a fixed quantity of mercury and rare gas is made to exist in the outer tube 1 thus to form a low pressure mercury-vapor discharge lamp having a bent discharge route. Accordingly, a part where the inner tubes 41 and 42 are connected to each other is almost eliminated without producing a useless positive column lengthy part thus to improve efficiency as wall as to remove unharmonious appearance due to blue luminance from the positive luminous column. |
