Patent ID: 8477436

Claim:
An objective lens for an endoscope comprising, in order from an object side: a front lens group having negative refractive power as a whole; a brightness aperture stop; and a rear lens group having positive refractive power as a whole; wherein said front lens group comprises, in order from the object side, a first lens group having negative refractive power that may include only a single lens; and a second lens group that may include only a single lens, said second lens group having a lens surface closest to the image side that is of a concave form directed toward the image side, said second lens group having positive refractive power as a whole; and the following condition (1) is satisfied: | f 0 /f 1 |<1.1 (1) where f 0 is the composite focal length of said front lens group, and f 1 is the focal length of said first lens group; and wherein there is an air space between said first lens group and said second lens group.