US Patent 7385711 Image formation system

An image formation system comprises a color image formation unit of a color image formation apparatus and a black-and-white image formation unit of a black-and-white image formation apparatus. A determining unit determines whether each page in an input job having both color pages and black-and-whites pages is a color page or black-and-white page. A control unit controls the color image formation unit to form the color pages, and the black-and-white image formation unit to form the black-and-white pages, based on results from the determining unit. In the event that both color pages and black-and-white page are to be formed on a single sheet, a selecting unit selects between a first mode wherein all pages are formed with the color image formation unit, and a second mode wherein the color pages are formed with the color image formation unit and the black-and-white pages are formed with the black-and-white image formation unit.