| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a diaphragm plate that prevents a lens from being separated from a lens barrel when air is blown onto the lens. Ž<P>SOLUTION: When a projection lens is assembled, a convergent lens is first fixed to the lens barrel 11. After the convergent lens is fixed, a diaphragm plate 14 is inserted into the lens barrel 11, and a caulking pin 11b projecting from a level difference 11a is inserted into the caulking hole 14b of the diaphragm 14. At the same time with this, a notch 14d fits onto a projection 11c. Thereafter, the diaphragm plate 14 is fixed to the lens barrel 11 by thermally caulking. After the diaphragm plate 14 is fixed, air is blown toward the convergent lens from the front surface 14e side of the diaphragm plate 14 through a diaphragm opening 14a, thereby removing foreign matter. When air is blown, the diaphragm plate 14 is elastically deformed such that its lower end is curved toward the front surface 14e side and the notch 14d is temporarily separated from the projection 11c, thereby causing air to escape toward the front surface 14e side. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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