Spectral colorimetric apparatus and image forming apparatus including the same

摘要

A spectral colorimetric apparatus includes a housing which includes a side wall. An outer surface of the side wall is an adjustment surface capable of adjusting a position of a light receiving member by moving in a state in which the light receiving member abuts on the adjustment surface. The light receiving member is supported by the side wall of the housing in a state in which the light receiving member abuts on the adjustment surface and receives a light beam that is dispersed by a concave surface reflection type diffraction element and passes through an opening portion. The adjustment surface is parallel to a tangential line at a part of a Rowland circle of the concave surface reflection type diffraction element, through which a light beam received by the light receiving member passes.