DOUBLE TUBE TYPE LOW PRESSURE MERCURY VAPOR ELECTRIC DISCHARGE LAMP AND LAMP DEVICE AND LIGHTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To facilitate the rising of light flux in the case of starting a low pressure mercury vapor electric discharge lamp under low temp. atmosphere and prevent excessive rising of temp. in an arc tube during stable operation causing decrease in the luminance. ;SOLUTION: In a light transmissive outer tube 20 having an air-tight space therein an arc tube 10 in which mercury and rare gas are sealed is contained. Between the two 10, 20 a heat transmission member such as silicone rubber 25 for connecting the two 10, 20 to each other in a heat transmissible manner is disposed. Thereby when the thus constructed lamp starts under the low temp. atmosphere the temp. increase in the arc tube 10 is facilitated with the heat insulation action in the heat insulating space in the outer tube 20. Even when the temp. in the tube 10 tends to rise the heat in the tube 10 escapes through the silicone rubber. Accordingly fluctuation in the luminance caused by the temp. change of the circumference can be restrained.;COPYRIGHT: (C)1997,JPO