| 摘要 |
PROBLEM TO BE SOLVED: To provide: a light source optical system capable of projecting a brighter image by reducing the volume of unconverted light returning to a light source from a wavelength conversion element; a light source device having the same; and an image display device.SOLUTION: A light source optical system, which guides light from a light source 1 to a fly-eye lens 40 comprising a plurality of lens cells, includes a phosphor 5 which converts blue light to fluorescence of a wavelength different from that of the blue light and emits the fluorescence as well as unconverted light of the blue light wavelength. The light source optical system further includes a mirror 3 comprising a region 31 having a property that directs the blue light to the phosphor, and a region 32 having a property that directs the fluorescence and unconverted light in a direction other than a direction toward the light source 1. The blue light enters the region 31 while the fluorescence and unconverted light enter both the region 31 and region 32. When viewed from an optical axis direction of the lens cells, the area of the region 31 and the area of the lens cells satisfy a predefined relationship. |
