According to an embodiment, an image reading device includes a photoelectric conversion unit, a white reference plate, a rotation unit, and a control unit. The photoelectric conversion unit includes an image reading sensor which converts light from an imaging position into image data. The white reference plate has a reading range which is a white reference value. The rotation unit rotates the photoelectric conversion unit so as to come to an angle at which a plurality of portions in the reading range of the white reference plate become imaging positions. The control unit sets a white reference value using a plurality of pixels on the white reference plate which are read using the photoelectric conversion unit which is rotated using the rotation unit.

According to an embodiment, an image reading device includes a photoelectric conversion unit, a white reference plate, a rotation unit, and a control unit. The photoelectric conversion unit includes an image reading sensor which converts light from an imaging position into image data. The white reference plate has a reading range which is a white reference value. The rotation unit rotates the photoelectric conversion unit so as to come to an angle at which a plurality of portions in the reading range of the white reference plate become imaging positions. The control unit sets a white reference value using a plurality of pixels on the white reference plate which are read using the photoelectric conversion unit which is rotated using the rotation unit.