IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To enable effective and accurate ejection of toner by setting the presence/absence and the amount of ejection of toner according to an image forming condition.SOLUTION: An image forming apparatus 100 comprises: an environment sensor 92 that detects the temperature and humidity inside an apparatus housing 100a; average printing ratio calculation parts (731, 732) that calculate the average printing ratio for every page; a solid discharge amount setting part 733 that, when the calculated average printing ratio is equal to or less than a threshold, sets a larger amount of toner as a solid discharge amount as the average printing ratio is lower and the detected temperature is higher; and a toner discharge control part 734 that discharges a toner inside a developing unit 4 to a photoreceptor drum 2 by the amount set by the solid discharge amount setting part 733.SELECTED DRAWING: Figure 2 【課題】画像形成条件に応じてトナーの排出の有無及び排出量を設定することで、効果的かつ精度良いトナー排出を可能とする。【解決手段】画像形成装置１００は、装置筐体１００ａ内の温度及び湿度を検出する環境センサ９２と、ページ毎に平均印字率を算出するピクセル計数部及び平均印字率算出部（７３１，７３２）と、算出された平均印字率が閾値以下の場合、平均印字率が低い程かつ検出した温度が高い程、より多い量のトナーをベタ吐き量として設定するベタ吐き量設定部７３３と、ベタ吐き量設定部７３３で設定された量だけ現像器４内のトナーを感光体ドラム２に排出するトナー排出制御部７３４とを備える。【選択図】図２