| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting system with its outer tube and protector glass prevented from being heated to a high temperature. SOLUTION: A protector glass ring 9 has an upper part 9a having an inner diameter larger than the diameter of a protector glass 11 and a lower part 9b having an inner diameter smaller than the diameter of the protector glass 11, and a part joining lower part 9b to the upper part 9a includes a step and, at this part, an end face of the lower part 9b serves as a glass hold part 9c. An upper surface of the glass hold part 9c is formed to have projections and recesses, and the protector glass 11 is supported by the projecting parts. If the temperature within the upper part 9a is raised by heat emitted by a lamp, the lamp and the protector glass 11 are prevented from being heated to a high temperature, because they are cooled by air supplied from the lower part 9b through gaps between the recessed parts of the glass hold part 9c and the protector glass 11. |
