Patent ID: 7385711

Claim:
An image formation system including a color image formation apparatus and a black-and-white image formation apparatus, the image formation system comprising: a color image forming section provided in the color image formation apparatus, for forming a color image; a black-and-white image forming section provided in the black-and-white image formation apparatus, for forming a black-and-white image; a determining section for determining whether each of pages in an input job in which both a color page and a black-and-white page exist is a color page or a black-and-white page; a controller for controlling the color image forming section to form an image for the color page and controlling the black-and-white image forming section to form an image for the black-and-white page according to the determination result of the determining section; and a selecting section for selecting one of a first mode and a second mode, the first mode being a mode in which, in a case where both a color page and a black-and-white page are to be formed on a single sheet, images for all the pages to be formed on the single sheet are formed by the color image forming section, the second mode being a mode in which, in a case where both a color page and a black-and-white page are to be formed on a single sheet, an image for the color page to be formed on the single sheet is formed by the color image forming section and an image for the black-and-white page to be formed on the single sheet is formed by the black-and-white image forming section, wherein the selecting section selects the first mode in a case where sheets having images formed thereon beforehand by the color image forming section are mixed without passing through the black-and-white image forming section, and selects the second mode in a case where the sheets are mixed with passing through the black-and-white image forming section.