Patent ID: 7929873
Filing Date: 2011-04-19
Classification: G03G

Abstract:
1. An image forming apparatus, comprising: an image carrier configured to carry an electrostatic latent image; a developing device configured to develop the electrostatic latent image with a two-component developer including toner and magnetic carrier; a toner supplier configured to supply the toner to the developing device; a toner concentration detector configured to detect toner concentration in the two-component developer inside the developing device; and a controller configured to detect first information to determine toner replacement amount in the developing device during a predetermined time period and second information to determine a charge characteristic of the toner in the developing device, wherein the controller changes a toner concentration control reference value based on the first information and the second information, and controls the toner concentration based on the toner concentration control reference value and an output from the toner concentration detector, wherein the controller determines an adjustment amount of the toner concentration control reference value based on the first information, and changes the adjustment amount based on the second information, and wherein the controller changes the adjustment amount of the toner concentration control reference value in a direction to increase toner concentration in the developing device when the second information indicates that the toner is more easily charged.