| 摘要 |
PROBLEM TO BE SOLVED: To provide a short arc lamp lighting device capable of extending the life of a lamp in the case of lighting at a lamp power less than a rated value, and provided a projection device saving electric power using the short arc lamp lighting device. SOLUTION: A DC power supply 14 is connected to a short arc metal halide lamp 12 via a step-down chopper circuit 11, and an ON period of the switching element Q of the step-down chopper circuit is controlled by the control signal from the control circuit 13 so that a lamp can be lighted by a rated lamp power and by a lamp power less than a rated value. Corresponding to the control of the lamp power of the control circuit, based on the existence of the input of an image signal to a projection device, the variable DC voltage source 15 of a blowing fan for blowing a lamp is controlled so that a rated blowing amount is blown at the lighting time of the rated lamp power, and when lighted at the electric power under the rating, the blowing amount is lessened than the rated blowing amount or the blowing is stopped and the lamp is turned on. |
