| 摘要 |
PROBLEM TO BE SOLVED: To provide an illumination optical system that can suppress a reduction in brightness of a projection image and an influence of light from a light source on a user, and a projection type display device using the same.SOLUTION: An illumination optical system comprises: a multiple reflection element 11 that includes a first surface and a second surface having different reflectances from each other and parallel to each other; a collimator lens 12; a fly-eye lens A13; and a fly-eye lens B14. A predetermined lens cell of a plurality of lens cells included in the fly-eye lens A uses light beams from the first surface and second surface to form a plurality of light source images at different positions from each other in a corresponding lens cell of a plurality of lens cells included in the fly-eye lens B.SELECTED DRAWING: Figure 1 |
