A photosensor system includes a photosensor array which is constituted by two-dimensionally arraying a plurality of photosensors and has a light-receiving surface, and a front light source which is arranged to face the light-receiving surface at an interval, and illuminates a rear surface of an object whose front surface is set on the light-receiving surface. An image reading assembly reads an object image by receiving light that is emitted by the front light source and passes through the object.