| 摘要 |
[Problem] To make possible reduced size, reduced diameter, and adequate correction of aberration, and to acquire a satisfactory image in an endoscope objective lens. [Solution] An endoscope objective lens comprises, in order from an object side, a negative first lens group (G1), a diaphragm, and a positive second lens group (G2). The first lens group (G1) is obtained by cementing, in order from the object side, a first lens (L1) and a second lens (L2), a concave surface of which faces the image side. The second lens group (G2) comprises, in order from the object side, a positive single-lens third lens (L3), and a cemented lens having a positive refractive power in which are cemented a fourth lens (L4) and a fifth lens (L5), either of which is a positive lens and the other is a negative lens. The Abbe numbers of the first lens (L1) and the second lens (L2) satisfy a predetermined conditional expression relating to the curvature radius of the object side and image side of the second lens (L2). |
