A line illumination device includes: a frame; a rod-shaped light-guiding member housed in the frame; a flexible substrate; and a light source that is provided on the flexible substrate and emits light to the light-guiding member. In the color image forming apparatus, the reading unit is controlled to start reading of a next document of the document corresponding to the images under image forming when the predetermined image forming unit finishes image forming among the plurality of image forming units before the color image forming is finished. Each bushing has an internal opening which is sized to create an open area flow for cooling or operating the nozzle and its attaching flap hardware.