| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve such a problem that stray light or the like is mixed into on-state light and the contrast of a projection image is degraded when a distance between on-state luminous flux and each luminous flux center of off-state luminous flux and stray luminous flux is reduced on the incident side of a projection lens. <P>SOLUTION: The projection lens for projector using a reflection type display element is provided with a movable diaphragm 70 which can move in accordance with the movement of a movable lens group in the optical axis direction, wherein an opening part 75 of the movable diaphragm 70 has a circular shape around an optical axis 69 of the projection lens, and a swelling part 73 which protrudes from a peripheral part in the stray luminous flux center direction into the opening part 75 is disposed on a part of the opening part 75. <P>COPYRIGHT: (C)2008,JPO&INPIT |
