Patent ID: 9366854
Filing Date: 2016-06-14
CPC Classification: G02B

Claim Text:
1. A re-imaging optical system that is provided between an image guide and a solid-state image-acquisition device and that re-forms an image transmitted through the image guide at the solid-state image-acquisition device, the re-imaging optical system being an object side telecentric optical system and comprising: a front group; an aperture stop; and a rear group, in this order from an object side, wherein the front group has a positive refractive power as a whole, the rear group is composed of two groups that are a positive lens disposed on the object side and a negative lens disposed on an image side, and has a positive refractive power as a whole, each of the positive lens and the negative lens is formed of a single lens or a cemented lens, and conditional expressions (1) and (2) below are satisfied: where fR1 is a focal distance of the negative lens, f is a focal distance of an entire system, and L is a total length from an object surface to an image surface.