| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an illumination optical system and a projection display apparatus for displaying a brighter image. <P>SOLUTION: The illumination optical system includes two lamp units where a positive electrode and negative electrode of a lamp are arranged along the optical axis of a concave mirror, a photosynthesis section for synthesizing light from one unit of two lamp units and light from the other unit, a condensing lens for condensing light from the photosynthesis section, and a light recursion section that is arranged between the photosynthesis section and the two lamp units and divides a part of emission light from the two lamp units to a luminous flux returned to the lamp and a luminous flux guided to the photosynthesis section. The photosynthesis section synthesizes the light from each unit by reflecting light emitting from the outside of the optical axis of the other unit with a first reflection section existing on the optical axis of the one unit and out of the optical axis of the other unit and a second reflection section existing out of the optical axis of the one unit. <P>COPYRIGHT: (C)2011,JPO&INPIT |
