| 摘要 |
PROBLEM TO BE SOLVED: To quickly warm up a discharge lamp at start while satisfying miniaturization requirements by brining a reflector close to the side face of a light guide unit. SOLUTION: A discharge lamp 4 is placed on the side face of a light guide unit 3, a reflector 5 reflecting the light of the discharge lamp 4 to the side face of the light guide unit 3 is provided, a heater 6 for heating at low temperatures is provided on the outer periphery of the discharge lamp 4, and an insulating ring 7 specified to have a greater outside diameter than the heater 6 is provided in such a way as to fit over the discharge lamp 4 from above the heater 6. Thereby the heat and electric charge of the heater 6 are not allowed to escape from the reflector 5 and the light guide unit 3. Thus, the discharge lamp 4 can be warmed up quickly at start while satisfying miniaturization requirements by bringing the reflector 5 close to the side face of the light guide unit 3. |
