| 摘要 |
PROBLEM TO BE SOLVED: To improve the cooling efficiency of an optical head unit constituted to include plural light valves and prisms. SOLUTION: A lamp housing unit 15, a light guide unit 16, an optical head unit 17, an electric power source unit 19 and a control circuit unit 20 for driving are arranged on a base plate 14. The control circuit 20 for driving is separated and unitized and is arranged atop the light guide unit 16 in such a manner that any one unit 201 does not overlap the optical head unit 17. A propeller fan 21 is mounted on the lower side of the optical head unit 17. Outdoor air is blown to the optical head unit 17 by the fan 21, by which the unit is cooled. At this time, the circuit unit 201 does not hinder the cooling and, therefore, the cooling efficiency may be improved. |
