Abstract: If it is desired to display the number of copies which can be outputted corresponding to the defined capacity of a developer which is determined by an image forming apparatus, a document which is thought to have a substantially average black ratio of the respective black ratios of images actually recorded by the image forming apparatus is prepared. The prepared document is set in reading means. An image of the set document is read by reading means. The black ratio of the image of the document is calculated on the basis of an output of the reading means. The number of copies which can be outputted corresponding to the defined capacity of the developer which is determined by the image forming apparatus is calculated on the basis of the calculated black ratio. The calculated number of copies which can be outputted is displayed.

Abstract: The present invention is directed to an image density control device in an image formation apparatus where a pattern of reference density on a sample original is exposed to light from an exposing light source to image the pattern on photoconductor, density of the resultant toner image is detected by a reflection-type photosensor, and parameters on image density are adjusted based upon results of detection by the reflection-type photosensor. In the image density control device in the image formation apparatus, the sample original is mounted on a cabinet of the image formation apparatus so that a distance from the exposing light source in illuminating the pattern of the reference density to the pattern of the reference density can be adjusted.