PURPOSE: An image reading device and method are provided to prevent the deterioration of image quality of a read image. CONSTITUTION: A light source(110) irradiates light to the document of a read object(180). The light source includes one or more LEDs(Light Emitting Diodes). A light source controller(120) controls the lighting time of the light source. An image is picked up with light reflected from the document. An image sensor(130) changes the image into an electric signal.
