Abstract: Provided is a controlling device for controlling an image reading apparatus that optically reads an original, which includes a lighting controlling section that controls a first lighting section and a second lighting section which are the first and second lighting sections provided in the image reading apparatus, form each of the linear light emitting regions, and irradiate the original with light from directions intersecting with each other, and the lighting controlling section includes a first mode unit that controls the first and second lighting sections in a first mode in which one of the first and second lighting sections irradiates the original, a second mode unit that controls the first and second lighting sections in a second mode in which both of the first and second lighting sections irradiate the original.