US Patent 7071979 Image sensing apparatus and method

An image sensing apparatus senses an image by illuminating a document by a light source including three light emitting diodes which emit light of red, green, and blue so that the light reflected from the document is incident on a sensor array which in turn generates an electric signal corresponding to the incident light, wherein a predetermined light emitting diode is also turned on during a period in which no image sensing operation is performed thereby making it possible to stabilize the intensity of light illuminating an image. Thus, the invention provides a high-performance and small-sized image sensing apparatus at a low cost.