| 摘要 |
PROBLEM TO BE SOLVED: To attain the cost reduction of a lens unit, to improve the assemblability of the lens unit, and to prevent the erroneous assembling. SOLUTION: The lens unit includes a 1st lens 1, an aperture diaphragm plate 4 of a prescribed diameter and a 2nd lens 2 which are successively arranged from an object side to an image field side, and also, a spacer 300 arranged between the 1st lens 1 and the 2nd lens 2, and the spacer 300 is constituted by joining a plurality of spacers 300a to 300d having the same shape, and the aperture diaphragm plate 4 is sandwiched between either two of the plurality of spacers. By having such the constitution that the plurality of spacers having the same shape are used, the manufacturing cost is reduced, and it can be assembled in both directions, then, the erroneous assembling is prevented, and also, since the installation position of the aperture diaphragm plate 4 is allowed to be located between either two of the plurality of spacers, the degree of freedom in design can be enhanced, and the aperture diaphragm plate can be arranged in a position corresponding to the optical design specification. COPYRIGHT: (C)2006,JPO&NCIPI
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