Patent ID: 7881629
Filing Date: 2011-02-01
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image carrier for carrying a latent image; a development device for developing the latent image on the image carrier into a toner image using a developer containing a toner and a magnetic carrier; a toner replenishment device for supplying replenishment toner to the development device; toner concentration detecting means for detecting a toner concentration of the two-component developer in the development device; toner concentration control means for controlling the toner concentration in the development device in accordance with a toner concentration control reference value that is referenced in order to control the toner concentration; a belt member provided in a position contacting the image carrier and stretched by a plurality of stretching members; toner pattern detecting means for detecting a toner pattern formed on the belt member; information detecting means for detecting information for learning a toner replacement amount in the development device over a predetermined time period; first toner concentration control reference value modifying means for modifying the toner concentration control reference value on the basis of a detection result of the information detecting means; and second toner concentration control reference value modifying means for modifying the toner concentration control reference value on the basis of a detection result of the toner pattern detecting means, wherein the first toner concentration control reference value modifying means and the second toner concentration control reference value modifying means operate in conjunction to modify the same toner concentration control reference value, and wherein an interval at which the second toner concentration control reference value modifying means modifies the toner concentration control reference value is varied in accordance with the toner replacement amount.