| 摘要 |
PROBLEM TO BE SOLVED: To provide an endoscope objective lens capable of excellently correcting chromatic aberration of magnification without increasing an entire length. SOLUTION: A first lens group having negative power, a diaphragm, a second lens group having positive power, and a third lens group having positive power at least in the periphery are arrayed in order from an object side, and a surface being the closest to an image side is concave in the second lens group, and the second lens group satisfies the following conditions, that is 0.05<|f/f0|, and f0/0. Provided that (f) defines the focal distance of the entire system, and f0 defines the focal distance of an air lens formed between the surface on a side closest to the image in the second lens group and the surface on a side being the closest to an object in the third lens group.
|
