Patent ID: 7394999

Claim:
An image forming apparatus capable of forming, according to an image information signal, an image on an image bearing member with a developer containing a toner, and outputting the image by a transfer operation onto a recording material, the apparatus comprising; detection means which detects an image characteristic of the image formed on the image bearing member; first control means which controls a toner concentration in the developer, based on a detection result by the detection means, of an image characteristic of a first reference image for a first control for controlling the toner concentration in the developer; second control means which controls an image parameter, different from the toner concentration in the developer, thereby controlling an image density, based on a detection result by the detection means, of an image characteristic of a second reference image for a second control, different from the first reference image for the first control; and correction means which receives detection results of both image characteristics of the first and second reference images, and which, based on the detection result of the image characteristic of either of the reference images for the first and second controls, corrects the other control.