An image reading apparatus is arranged to illuminate a transparent or
transmissive original with light fluxes emitted by a plurality of light
emission parts which differ in wavelength characteristic from each other,
to select by means of a reflection mirror the wavelength characteristics
of light fluxes emitted from the light emission parts, and to control each
of the light emission parts every time a scanning motion is made by an
original-placing board relative to an image pickup part.
