Power-saving discharge lamp

摘要

A power-saving discharge lamp 1 wherein gap control material 6 is provided in a clearance between an internal bulb 2 and an external bulb 5, having a smaller thickness than the dimension of the clearance. Nonuniformity of the clearance between the both bulbs caused by difficulties in supporting the internal bulb 2 while welding the external bulb 5 is eliminated and a suitable clearance is automatically provided by the gap control material 6 to prevent degradation of the heat insulation effect.