ILLUMINATION LIGHT SOURCE DEVICE, PROJECTOR WITH THE ILLUMINATION LIGHT SOURCE DEVICE, AND CONTROL METHOD FOR PROJECTOR

摘要

PROBLEM TO BE SOLVED: To provide an illumination light source device that is able to reduce irregularity of the brightness of light used for illumination of a screen, while preventing a decrease in efficiency of generation of fluorescence generated from a fluorescent body.SOLUTION: An illumination light source device comprises: an optical path splitting member 2e configured to split light from a light source 2 into an optical path for light used for excitation of fluorescent body 2h and an optical path for light used for emission to a screen; a first diffusion member 2v1 provided for the optical path for light used for exciting light from the light source 2 for the fluorescent body 2h, and a second diffusion member 2v2 provided for an optical path for light used for light from the light source 2 for emission to the screen. The first diffusion member 2v1 and the second diffusion member 2v2 are arranged in the respective optical paths such that the degree of diffusion of light by the second diffusion member 2V2 is higher than the degree of diffusion of light by the first diffusion member 2v1 when a comparison is made at an equal distance from the light source between the degree of diffusion of light used for excitation of the fluorescent body 2h and the degree of diffusion of light used for emission to the screen.