Patent ID: 6876471

Claim:
An image reading device for reading an image while conveying an original on which the image is recorded, comprising: a plurality of light emitting element units, at each of which a plurality of light emitting elements are arrayed along a first direction which is a direction perpendicular to the original's conveyance direction, said plurality of light emitting element units being linearly disposed along the first direction; an optical member for irradiating light emitted from said plurality of light emitting element units across at least a substantially entire width of the original in the first direction; and photoelectric conversion elements which are disposed in correspondence with said plurality of light emitting element units, receive light that is one of transmitted through and reflected from the image, and conduct photoelectric conversion of the received light, wherein the image is read while at least one original is conveyed, the original having a width dimension corresponding to a width dimension of one of said plurality of light emitting element units or a combined width dimension of at least two of said plurality of light emitting element units; wherein at least one light emitting element unit for emitting light is selected among said plurality of light emitting element units in accordance with at least one of a first direction dimension of the original, a number of originals and a magnification at which the original is to be read.