公开(公告)号：US20180113293A1

公开(公告)日：2018-04-26

申请号：US15784725

申请日：2017-10-16

Applicant: OLYMPUS CORPORATION

Inventor： Kenichiro ABE ,  Hirokazu KONISHI ,  Masahiro SAKAKURA ,  Takashi KASAHARA ,  Yuso FUJITA

IPC: G02B21/02 ,  G02B9/18

CPC classification number: G02B21/025 ,  G02B9/18 ,  G02B21/02

Abstract: An objective includes a first lens group that has a positive refractive power and a second lens group that has a negative refractive power. The objective includes a first negative lens and satisfies 0.005≤dol/hol≤0.1   (1) 0.005≤hmin/hl≤0.72   (2) 10 mm≤L≤100 mm   (3) 0.1≤L/f≤31   (4) when do1is a thickness of the first negative lens, ho1 is an axial marginal ray height on a lens surface on the object side of the first negative lens, hmin is a minimum value of an axial marginal ray height in the second lens group, hl is a height of an axial marginal ray on a lens surface of the objective that is situated closest to the image side, L is a length of the objective, and f is a focal length of the objective.