| 摘要 |
PURPOSE:To project only polarized light with high efficiency by combining an optical transmission element consisting of two kind of lens plates with a polarized light converting element and converting random polarized light into specific linear polarized light, and superposing and coupling the resulting luminous flux and guiding it to a lighting area. CONSTITUTION:The random polarized light 11 from a light source 10 is split by a polarization beam splitter 16 as a polarized light splitting element into linear polarized lights which are a P polarized light 12 and an S polarized light 13; and the P polarized light passes through a lambda/2 phase plate 14 to become an S polarized light and the S polarized light 13 is projected as it is. Further, the optical transmission element consisting of the 1st lens plate 21 and 2nd lens plate 22 is arranged between the polarized light converting element and lighting area 22, and the split pieces of luminous flux are converted into pieces of luminous flux which are as large as the lighting area 23, and then coupled together one over the other and guided to the lighting area 23. Consequently, even if the intensity of the luminous flux from the polarized light converting element is uneven, the unevenness of the intensity distribution is averaged by the thinning and coupling of the luminous flux, thereby obtaining an excellent light distribution which is free from intensity unevenness and color unevenness in the lighting area 23. |
