| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent dust from infiltrating a projection optical system in a projection-type image display apparatus, using a catoptric system as the projection optical system. <P>SOLUTION: An optical path, directed from a DMD 3 to the concave mirror 25 of the projection optical system 6, is in a sealed cavity 54 surrounded by an image forming element holding plate 46 for holding the DMD 3, the 1st cylindrical part 41 of the lower optical holding member 9 and a cover glass 53. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
