The present disclosure relates to an image reading device, an image forming apparatus including the same, and an image reading method.
Generally, there is known a light source switching type image reading device that obtains color image data by sequentially lighting light sources (LED, or the like) of three colors corresponding to R (red), G (green), and B (blue) and by reading, at that time, light data received by a line sensor as R data, G data, and B data, respectively.
In the light source switching type image reading device, since image data of respective colors are read while a document and the line sensor are relatively moved in a sub-scanning direction at a constant speed, the reading positions of the respective colors in the document do not coincide and are shifted in the sub-scanning direction. As a result, for example, each color is sometimes different from that in the document at, for example, a boundary portion of the color. Under such circumstances, there is known an image reading device that is able to correct such a color shift by correcting the image data of the respective colors that are read.