Patent ID: 8036554

Claim:
An image forming apparatus comprising: a photoreceptor; an exposure device that forms an electrostatic latent image on the photoreceptor by exposing the photoreceptor; a developing device including (i) a developer tank in which a two-component developer containing toner and carrier has been stored and (ii) a developing roller that forms a toner image on the photoreceptor by supplying, to the electrostatic latent image formed on the photoreceptor, the toner contained in the two-component developer stored in the developer tank; a supply device that corrects a toner density of the two-component developer by supplying toner to the developer tank; a detection device that detects an amount of toner of the toner image formed on the photoreceptor; and a control device that controls operation of each of the photoreceptor, the exposure device, the developing device, the supply device, and the detection device, upon detection of replacement of the two-component developer stored in the developer tank, the control device controlling the operation so that a density correction process is performed, the density correction process being a process, including (a) a formation first step of forming a reference toner image on the photoreceptor, (b) a detection first step of detecting an amount of toner of the reference toner image, and (c) a supply step of supplying a predetermined amount of toner to the developer tank when the amount of toner detected in the first detection step is less than a threshold, by which process the supply step, the formation first step and the first detection step are in this order until the amount of toner detected in the first detection step becomes not less than the threshold, wherein: when the amount of toner detected in the first detection step is not less than the threshold, the control device controls the operation so that a second formation step of forming the reference toner image on the photoreceptor and a second detection step of detecting an amount of toner of the reference toner image formed in the second formation step are performed; and when a difference between the amount of toner, detected in the first detection step, which is not less than the threshold and the amount of toner detected in the second detection step exceeds a predetermined value, the control device controls the operation so that the density correction process is performed again after the two-component developer stored in the developer tank has been stirred.