PROJECTION DISPLAY DEVICE AND LIGHTING DEVICE

PROBLEM TO BE SOLVED: To increase brightness while suppressing the increase in width of light emitted from a light source device.SOLUTION: A light source device 100 includes first and second lamps 110A and 110B, a wheel 121, and a motor 122 for driving the wheel 121. A transmission region 125 which transmits light of the first lamp 110A to direct the light to a light guide unit 200 and a reflection region 124 which reflects light of the second lamp 110B to direct the light to the light guide unit 200 in a state where an optical path of this light overlaps an optical path of the light of the first lamp 110A, are formed on the wheel 121. A control circuit 40 periodically increases/decreases an output of the first lamp 110A with an allowable output Pas the center and periodically increases/decreases an output of the second lamp 110B with the allowable output as the center inversely to increase/decrease timing of the output of the first lamp 110A, and operations of the lamps 110A and 110B and the operation of the motor 122 are synchronized with each other so that light of the output higher than the allowable output is emitted from two lamps 110A and 110B alternately.