Objective optical system for endoscope and endoscope

Abstract

An objective optical system for an endoscope forms an intermediate image at a position conjugate to an object surface and forms the intermediate image on an imaging plane again, and is adapted to satisfy Conditional expressions (1) to (3) in a case in which a maximum effective image height on the imaging plane is denoted by HI, a focal length of the entire system is denoted by f, an effective luminous flux diameter on a lens surface closest to an object is denoted by FD, a maximum effective luminous flux diameter among effective luminous flux diameters on lens surfaces of the entire system is denoted by BD, and a paraxial relay magnification of the intermediate image on the imaging plane is denoted by βR. 0.7<HI|f|  (1) FD/BD<0.5   (2) −2<βR<−0.8   (3)

Dependencies are inferred from the claim text.