| 摘要 |
PROBLEM TO BE SOLVED: To enhance environmental tolerance while maintaining characteristics in which an imaging lens is compact and has a long back focusing distance. SOLUTION: The imaging lens includes a front group U1 having positive power, a diaphragm St, and a rear group U2 having positive power in order from an object side. The front group U1 includes a first lens L1 having negative power and making meniscus shape with a convex face toward the object side, and a second lens L2 having positive power and making a lens face R4 of an image side a convex face in order from the object side. The rear group U2 includes a third lens L3 having negative power and making a lens face R6 of the object side a concave face, a fourth lens L4 having positive power and making a lens face R9 of the image side a convex face, a fifth lens L5 making both convex shape, and a sixth lens L6 having negative power and making meniscus shape with a convex face toward the image side in order from the object side. All of the first lens to the sixth lens are glass sphere single lenses. COPYRIGHT: (C)2010,JPO&INPIT |
