TEMPERATURE CONTROL OF ARC TUBE OF FLUORESCENT LAMP

摘要

A fluorescent lamp includes an arc tube 12 comprised of light transmissive material. The arc tube can be for a compact fluorescent lamp (CFL). A discharge sustaining fill 14, which may include mercury and an inert gas, is sealed in the interior of the arc tube. Electrodes are disposed in the sealed interior of the arc tube. An outer envelope 22 is disposed around and spaced apart from the arc tube. The outer envelope can take the form of a conventional incandescent light bulb, candle, globe-shape or reflector shape. The outer envelope includes an opening 24. The arc tube includes a hollow protrusion 26 that extends adjacent or into the opening. This can provide the arc tube with a lower temperature near the protrusion that can approximate the temperature of the outer envelope (a cold spot). This can regulate the vapor pressure of liquid (e.g., liquid mercury) in the arc tube.