| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection lens, equipped with a diaphragm mechanism capable of making a light-shielding member move substantially linearly, using a simple structure. SOLUTION: The diaphragm mechanism 1 is equipped with a fixed diaphragm 2 where an aperture 3 is formed, a movable diaphragm 4 for changing the shielding area of the aperture 3, and a pair of coupling members 5 and 6, attached to the movable diaphragm 4 and at a position outside the movable diaphragm 4 and supporting the movable diaphragm 4. A pair of coupling members 5 and 6 can rotate with the center at fulcrums 7 to 10 at respective attached positions, and the respective fulcrums 7 to 10 are positionally arranged so that four lines 11 to 13 linking the respective fulcrums 7 to 10 form a parallelogram or a rectangle, then the position of the movable diaphragm 4 is changed, to adjust the shielding area of the aperture 3. COPYRIGHT: (C)2006,JPO&NCIPI
|
