Patent ID: 8515299

Claim:
An image forming apparatus comprising: an image forming unit including an image carrier for carrying an image containing a toner image to be transferred onto a sheet and a correcting toner image to be used for adjusting a density of the toner image, the image forming unit being provided for forming the toner image in an image area of the image carrier, and forming the correcting toner image in a non-image area of the image carrier; a detection sensor for detecting density information of the correcting toner image formed in the non-image area by the image forming unit; and a controller for causing the image forming unit to correct an image forming condition based on the density information detected by the detection unit to execute a stabilization control, wherein the controller causes the image forming unit to form a plurality of correcting toner images different in density over a plurality of non-image areas, and when receiving at least one information of interruption information, mode switching information and job switching information during execution of the stabilization control, the controller determines which mode is set between a processing speed priority mode, which puts priority on processing time, and an image quality priority mode, which does not put priority on processing time, when the controller judges the mode to be the processing speed priority mode, after the controller thins out or deletes a fixed number of correcting toner images before patch formation, or after the controller reduces a formation size of correcting toner images, or after the controller groups correcting toner images every same color to change a formation order, the controller causes the image forming unit to form correcting toner images continuously on the image carrier and when the controller judges the mode to be the image quality priority mode, after the controller changes a formation order of the correcting toner images to a predetermined order, the controller causes the image forming unit to form correcting toner images continuously on the image carrier, causes the detection sensor detect density information of the continuously formed correcting toner images, and then causes the image forming unit to finish a processing operation in the stabilization control under execution.