| 摘要 |
PURPOSE:To suppress changes in characteristics such as lamp luminous flux in the lighting direction, by forming the coolest point on the tip of a glass tube opposite to an electrode and disposing an amalgam forming material in the vicinity of a one-sided electrode and using an amalgam forming material-side electrode as an anode and lighting the lamp in the form of a DC circuit or an AC circuit superposed by a DC circuit. CONSTITUTION:An amalgam forming material 25 is disposed in the vicinity 9 (on the base side) of a one-sided electrode of a luminous tube 23. Therefore, as if a temperature at the base-side end part rises excessively due to power dissipation of a lighting circuit at the time of lighting under the base, mercury vapor pressure of the amalgam forming material 25 becomes lower than that of a mercury unit so that a level of vapor pressure can be controlled within an appropriate range. When an electrode 9 on the side of the amalgam forming material 25 is used as an anode and the lamp is lighted in the form of a DC circuit or an AC circuit superposed by an DC circuit, a mercury cataphoresis phenomenon peculiar to the low-pressure mercury vapor discharge lamp can be suppressed so that miniaturization, compactness, and inexpensiveness for the circuit can be realized. |
