Patent ID: 7657194
Filing Date: 2010-02-02
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image support on which an electrostatic latent image is formed; a developing device for visualizing the electrostatic latent image by adhering toner to the electrostatic latent image on the image support by means of a developing roller; an image storage for storing image information to be printed; an exposure device for forming the electrostatic latent image on the image support in accordance with the image information stored in the image storage; a toner concentration detector for detecting a toner concentration of a developer in the developing device; a toner supply device for supplying the toner to the developing device based on the toner concentration obtained by the toner concentration detector, wherein the image forming apparatus is controlled so that the toner is supplied to the developing device in accordance with the amount of toner that has been consumed as an image output proceeds; a toner concentration storage which, as to a plurality of developer blocks into which the developer that circulates in the developer device is virtually divided across an image forming width, stores the detected toner concentration of each developer block, detected by the toner concentration detector, separately for every developer block; a toner consumption predictor for predicting a first predicted toner consumption of the toner that is expected to be consumed and/or was consumed from the developer of every developer block during the first circulation in accordance with the image information, based on a developer's speed of conveyance in the developing device and a print processing speed; and a toner concentration estimator for estimating, for every developer block, a toner supply point estimate as the toner concentration at a point where toner is supplied, by subtracting the first predicted toner consumption from the associated detected toner concentration and setting up a toner supply target value of the toner to be supplied from the toner supply device to the developing device in accordance with the predicted toner consumption during a second circulation that follows the first circulation, of the developer inside the developing device.