Viewfinder optical system of inverted Galilean type with great magnification

摘要

The present invention provides a viewfinder optical system of inverted Galilean type which has a great magnification relative to the diameter of the objective lens without increasing the number of parts. The viewfinder optical system consists of, from the object side to the eye side, an objective lens component having a negative refractive power and an eyepiece lens component having a positive refractive power. The eyepiece lens component has a convex surface at the eye side. The viewfinder optical system fulfills the following conditions: 0.4L<d3<0.85L -1.4<L/R4<-0.8 R4<0 0.35<¦R2/R4¦<0.65 wherein: L represents the total length of the whole viewfinder optical system; d3 represents the axial thickness of the eyepiece lens component; R2 represents the radius of curvature of the eye side surface of the objective lens component; and R4 represents the radius of curvature of the eye side surface of the eyepiece lens component.