| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide-angle lens which is suitable to an imaging camera such as a genuine decision device. SOLUTION: The wide-angle lens is constituted by arranging, in order from an object side, a first meniscus lens 1 which has negative refracting power and is convex to the object side, a second lens 2 which has positive refracting power, a third biconvex lens 3 which has positive refracting power, a fourth meniscus lens 4 which has negative refracting power and is concave to the object side and connected to the third lens 3, an aperture stop SD having a designated diameter, a fifth biconcave lens 5 which has negative refracting power, a sixth biconvex lens 6 which has positive refracting power, and a seventh biconvex lens 7 which has positive refracting power. Consequently, the compact wide-angle lens which has a wide view angle in close-up photography, has high image-side telecentricity, can obtain sharp distortion-free images, and is suitably mounted on equipment with a limited arrangement space is obtained without employing an aspherical surface. COPYRIGHT: (C)2007,JPO&INPIT
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