Patent ID: 7733513

Claim:
An image forming apparatus comprising: a color image reading device capable of scanning color documents to obtain color image data; a monochrome image reading device configured to simultaneously scan both surfaces, including a first surface and a second surface, of a document to obtain monochrome image data of the document; a first storage unit configured to store therein the monochrome image data to delay a timing of image formation based on the monochrome image data; an image processing unit that executes a predetermined image processing on both the color image data and the monochrome image data at one time by use of a path for processing the color image data to obtain processed image data, the color image data being color image data read by the color image reading device and the monochrome image data being monochrome image data stored in the first storage unit; and a second storage unit that stores therein the processed image data; and an image forming unit that forms an image based on the processed image data, wherein the image processing unit includes: a monochrome processing unit that carries out the predetermined image processing on the monochrome image data by use of common line delay FIFOs provided on paths for the monochrome data and the color image data; and a color processing unit that carries out the predetermined image processing on the color image data, the image forming apparatus further comprising a selecting unit that selects any one of the monochrome processing unit and the color processing unit, wherein the color image reading device includes: an automatic document feeder that allows simultaneous scanning of the both surfaces of the document; and a plurality of color processing units, wherein a color processing unit is selected based on processing speed of the second storage unit.