Real image finder optical system having half mirror and information display surface within eyepiece optical system

摘要

A real image type finder optical system is provided with an objective optical system having a positive power, an erecting optical system for erecting a real image formed by the objective optical system and an eyepiece optical system for observing the real image formed by the objective optical system and erected by the erecting optical system. An information display surface provided in the eyepiece optical system, the information display surface displaying information to be observed in a field of view of the finder optical system. A partial mirror surface is provided within the eyepiece optical system, on an object side with respect to the information display surface. The partial mirror surface allows a part of light incident from the object to pass therethrough, and reflects light incident from the information display surface towards the eye side.