发明名称 |
Optical unit and projection-type image display apparatus using the same |
摘要 |
A technique according to the present invention allows a projection-type image display system to suppress the temperature rise of the polarization split devices and secure high image quality. Polarization split means has a polarization split device arranged in a medium with a refractive index larger than 1. The polarization split device has a polarization split surface on which a diffractive grating structure is formed to polarize and split light. An air layer is formed in contact with the polarization split surface. In a projection type image display apparatus or an optical unit using this apparatus, light fluxes are polarized and split by the polarization split means before irradiated to light valves and after modulated by the light valves and color composition is made from the polarized and split light fluxes before enlarged and projected by a projection lens unit.
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申请公布号 |
US7255444(B2) |
申请公布日期 |
2007.08.14 |
申请号 |
US20050061055 |
申请日期 |
2005.02.18 |
申请人 |
HITACHI, LTD. |
发明人 |
NAKASHIMA TSUTOMU;YATSU MASAHIKO;HIRATA KOJI |
分类号 |
G03B21/14;G02B5/06;G02B27/18;G02B27/28;G02B27/44 |
主分类号 |
G03B21/14 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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