Patent ID: 9225867
Filing Date: 2015-12-29
Classification: H04N

Abstract:
1. An image reading apparatus, comprising: a first illumination unit and a second illumination unit each having a plurality of light sources, each illumination unit is configured to irradiate light from the light source to a document reading position, the plurality of light source include a first light source and a second light source, the first light source emits light in a first color and the second light source emits light in a second color which is different from the first color; a light receiving unit configured to receive reflection light from a document to which light is irradiated by the first illumination unit and the second illumination unit, and to output, in response to a line synchronization signal, a first image signal in accordance with received light quantity; and a control unit configured to independently control 1) a turn-on period of each of the plurality of light sources in the first illumination unit and 2) a turn-on period of each of the plurality of light sources in the second illumination unit, in response to the line synchronization signal, wherein: the control unit is further configured to control, when reading the document, to turn on the light source of a same color by the first illumination unit and the second illumination unit within a line cycle defined in response to the line synchronization signal, and; the control unit is further configured to control the first illumination unit and the second illumination unit such that a center position of the turn-on period of each of the plurality of the light sources in the first illumination unit coincides with a center position of the turn-on period of each of the plurality of the light sources in the second illumination unit, within the line cycle defined in response to the line synchronization signal.