Imaging device, medium type determining device, and image forming apparatus

Abstract

An imaging device including a light source; a two-dimensional image sensor that receives reflected light from a subject containing specular light of the light source and outputs an image of the subject; a light transmission member disposed in an optical path of light emitted from the light source to the subject; and a light shielding unit that, when a position on the subject at which light from the light source is regularly reflected and enters the two-dimensional image sensor is defined as a first specular position, whereas a position on the light transmission member at which light from the light source is regularly reflected and enters the two-dimensional image sensor is defined as a second specular position, shields the light directed from the light source toward the second specular position without shielding the light directed from the light source toward the first specular position.