IMAGE FORMATION OPTICAL SYSTEM AND IMAGE PICKUP DEVICE

摘要

Provided are an image formation optical system which can be suitably used in an endoscope having a small diameter even when the angle of view thereof is super wide, and an image pickup device. Specifically disclosed is an image formation optical system (1) which is configured from a negative front group (FG), an aperture stop (S), and a positive back group (BG) in sequence from the object side, the front group (FG) being configured from a negative first lens (L1) and a negative second lens (L2) in sequence from the object side, and the back group (BG) being provided with a cemented lens (CL) formed by cementing at least three lenses (L5, L6, L7).