Pentagonal roof reflecting mirror assembly for single lens reflex cameras

摘要

A pentagonal roof reflecting mirror assembly for use in a viewfinder optical system of a single lens reflex camera is provided. The roof mirror assembly is of a modular form and includes an upper roof member and a lower roof support member that can be fastened together to form an enclosure that prevents the entrance of dust. The upper roof portion includes at least a pair of roof walls provided with a first and second mirror. The lower roof support member includes at least a lower light transmission wall and a side front wall provided with a third mirror positioned opposite to the first and second mirrors. The lower roof support member is molded of a transparent plastic material to permit light flux for the viewfinder optical system to enter the enclosure through the lower light transmission wall. Optical elements such as prisms, fresnel lens, plano-convex and plano-concave lenses can be molded as an integral part of the support assembly.