| 摘要 |
PURPOSE:To suppress the quantity of heat radiated toward the inside of a lighting circuit, by interposing a heat conductive plate at the junction between a discharging container and a lighting circuit container, exposing a part of said conductive plate to the external space and installing a heat insulating plate between said conductive plate and said lighting circuit container. CONSTITUTION:A heat conductive plate 9 made of Al-plate or the like is installed in close contact with the outsides of a stem 3, and the outside peripheral part of this conductive plate 9 is directly exposed to the external space. A container 6 housing the lighting circuit is installed on the conductive plate 9; and in the container 6 a heat insulating plate 8 is installed in contact with the conductive plate 9. In this way, the quantity of heat caused by discharge can be directly radiated to the external space by means of the conductive plate 9 by transmitting the heat through the stem 3, so that the quantity of heat can be effectively prevented from flowing into the space housing the lighting circuit. |
