ENDOSCOPE OBJECTIVE OPTICAL SYSTEM

摘要

Provided is a small endoscope objective optical system that allows stereoscopic viewing even though a wide angle is used, that reduces the F-number, and that also reduces vignetting.;Provided. is an endoscope objective optical system that consists of, sequentially from the object side, a negative first lens group, a positive second lens group, and a pair of third lens groups that are disposed side-by-side in the direction of parallax and that form two optical images with parallax, wherein aperture stops are individually provided in the third lens groups, and conditional expression M below is satisfied:;Fob_n/Fob_p>−0.5   (1),;where Fob_n is a focal length of the first lens group, and Fob_p is a focal length of the second lens group.

主权项

1. An endoscope objective optical system that consists of, sequentially from the object side, a negative first lens group having a single central axis, a positive second lens group having a single central axis, and a pair of third lens groups that are disposed side-by-side in a direction of parallax and that form two optical images with parallax,
wherein the negative first lens group consists of, sequentially from the object side, a negative lens, a positive lens, and a negative lens; wherein the positive second lens group consists of, sequentially from the object side, a cemented lens and a positive lens; and wherein aperture stops are individually provided in the third lens groups, and conditional expression (1) below is satisfied:
Fob_n/Fob_p>−0.5   (1),where Fob_n is a focal length of the first lens group, and Fob_p is a focal length of the second lens group.