ILLUMINATOR AND PROJECTION TYPE DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To make the divergent angle of a light source which is fetched as illuminating light large in an optical system that irradiates a light modulation element with the same polarized wave component by using 1st and 2nd lens arrays and a polarized light changing element. SOLUTION: When the image-formation position (f) of the 1st lens array is set to the position (y) of an aperture positioned on a liquid crystal display element side, an angleθ2 formed by a light beam L linking the intersection pL of a light beam B and the aperture position (y) on the extension of the light beam B with the center of the 1st lens array and an optical axis becomes the maximum fetched divergent angleθ2 in this case (b). When the image- formation position (f) of the 1st lens array is set to the intersection of the light beams A and B, the divergent angle of the light source is effectively fetched. Assuming that the length of the shorter optical path of the respective optical paths of P polarized light and S polarized light separated by the polarized light changing element 60 is S and the length of the longer optical path thereof is L, they are within the range of S