According to one embodiment, an imaging device array includes a plurality of imaging devices integrally including an incidence surface that converges light in the primary scanning direction, plural reflective surfaces that reflect light from the incidence surface multiple times, and an exit surface through which light that has reflected at the plural reflective surfaces exits the array. At least one of the plural reflective surfaces is formed at the apex of a protrusion that protrudes outwardly from the surface of the array, and the light that is output from the exit surface is imaged at an image point.