A scanner having: a first mirror having multiple concavities configured to reflect light from a document; a sensor configured to sense light reflected by a concavity of the first mirror; and a wall disposed to the first mirror and protruding from between the multiple concavities.

A reading apparatus includes an image sensor provided at a terminal end of an optical path, a diaphragm that restricts a quantity of light traveling along the optical path, a concave mirror provided adjacent to and on an upstream side of the diaphragm in the optical path and forms a portion of the optical path, and a convex mirror provided on the upstream side of the concave mirror in the optical path and forms another portion of the optical path.

An image reading apparatus includes a light source, a light receiving unit, and an optical system. The light receiving unit includes a plurality of light receiving elements. The optical system includes a plurality of optical components for splitting the light reflected from the object to be read, and guiding the split light to each of the plurality of light receiving elements. The plurality of optical components include a splitting component that splits the light reflected from the object to be read in a direction corresponding to a main direction, and a common component provided with a common portion. The common portion has an optically acting area causing a common effect on the tight split by the splitting component. A cross sectional shape of the optically acting area orthogonal to a direction corresponding to the main direction is the same shape along the direction corresponding to the main direction.

A reading module has a light source, an optical system, and a sensor. The optical system images, as image light, reflected light of light radiated from the light source to a document. In the sensor, the image light imaged by the optical system is converted into an electrical signal. The optical system has a mirror array and an aperture stop portion. In the mirror array, reflection mirrors are coupled together in an array in the main scanning direction. The aperture stop portion has a first aperture adjusting the amount of the image light reflected from a reflection mirror and a second aperture shielding stray light entering the first aperture from an adjacent reflection mirror. Between the first and second apertures, a reflection reduction mechanism is provided that reduces reflection, toward the first aperture, of light other than the image light traveling from the second to first aperture.

An image reading apparatus includes a light source that emits light in a main scanning direction to a subject to be read, a light receiving unit that receives light reflected by the subject to be read, and an optical system that images the light reflected by the subject to be read and guides the light to the light receiving unit. The optical system includes a reflector mirror that reflects the light reflected by the subject to be read, and an optical element that is disposed adjacent to the reflector mirror and images the light reflected by the subject to be read. The optical element is held by the reflector mirror.