Patent ID: 9678327
Date: 2017-06-13
CPC Classifications: G02B

Claim:
1. An endoscope objective lens consisting of, in order from an object side, a first lens group having a negative refractive power, a stop, and a second lens group having a positive refractive power, wherein at least one of the first lens group and the second lens group comprises only one cemented lens which is formed by a positive lens and a negative lens cemented together, the entire system comprises at least one single lens having a positive refractive power, and the condition expressions (1) and (2) below are satisfied: where f is a focal length of the entire system, Dp is a center thickness of a lens with the smallest center thickness among the at least one single lens having a positive refractive power, Dc is a center thickness of a cemented lens with the smallest center thickness among the at least one cemented lens, Lf is a distance along an optical axis from the most object-side lens surface to the stop, and Lr is a distance along the optical axis from the stop to the most image-side lens surface.