Parallax correcting mechanism for real image type viewfinders

Abstract

A parallax correcting mechanism for a real image type viewfinder, particularly for a real image type viewfinder having a zoom function of high magnification and allowing a desired parallax correction to be easily achieved by swinging a housing for an erecting optical system relative to a housing for an objective side optical system and thereby adjusting a relative position between an optical axis of the objective side optical system and an optical axis of the erecting optical system at its incidence side. More specifically, the housing for the objective side optical system containing therein lens holders serving to hold objective lenses respectively, includes a support hole at a position thereon appropriately spaced from a common optical axis of these objective lenses. A prism holder serving to hold prisms forming the erecting optical system is provided with a support pin projecting therefrom so as to be loosely inserted into the support hole so that the prism holder may be pivotally moved relative to the housing for the objective side optical system around the support pin. This pivotal movement allows the optical axis of the prism at its incidence side to be adjustably positioned relative to the optical axis of the objective lenses, and thereby allows a desired parallax correction to be achieved. An eyepiece is held by an eyepiece holder formed as a part of the prism holder.