LIGHT SOURCE DEVICE AND IMAGE PROJECTION APPARATUS USING LIGHT SOURCE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a light source device capable of directly detecting function deterioration of a diffusion member without decreasing illumination efficiency of a laser beam.SOLUTION: The light source device of the invention comprises: laser sources 1a-1c emitting laser beams P; a diffusion member 4 provided on a travelling optical path of the laser beam P, and having an incidence plane 4a which the laser beam P enters and an emission plane 4b from which the laser beam P entering the incidence plane 4a is diffused and emitted; and a light-receiving member 5 provided in a position not blocking the travelling optical path of a laser beam P' emitted from the emission plane 4b and used as an effective light flux, and receiving a laser beam P" which is ineffective in the diffusion member 4 when transmitting through the diffusion member 4. The function deterioration of the diffusion member 4 is determined by the light-receiving member 5 detecting the ineffective laser beam P".