Patent ID: 8879928

Claim:
An image forming apparatus configured to perform image formation on a recording material, the apparatus comprising: an image carrier configured to carry a developer image; a developing device including a developer storage portion configured to store a developer and configured to develop an electrostatic latent image formed on the image carrier; a remaining amount detection device configured to produce information relating to the remaining amount of the developer stored in the developer storage portion; and a control device configured to transmit an information signal relating to a usage limit of the developing device, wherein the developing device is a developer carrier that carries the developer in a confronting relationship with the image carrier, wherein the control device is configured to calculate a deterioration degree based on a deterioration coefficient that represents the deterioration degree of the developer per unit rotation time of the developer carrier and the rotation time of the developer carrier, wherein the deterioration coefficient is set to be greater when a residual developer amount is smaller, compared to a value when the residual developer amount is greater, and wherein the control device generates the information signal when a cumulative deterioration degree value exceeds a predetermined value.