| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of stabilizing toner concentration by appropriately supplying the toner. <P>SOLUTION: The image forming apparatus 100 includes a developing device 2, including a developing tank 111, first and second conveying members 112 and 113 for performing circulative conveyance of a developer, a developing roller 114 and a toner supply port 115a; a toner supply device 22 for supplying the toner to the developing device 2; a toner supply detecting sensor 119 for detecting whether the toner is supplied; and a toner concentration control means for instructing to supply the toner, when the toner concentration inside the developing device 2 becomes less than a predetermined value. The image forming apparatus also includes a toner supply amount changing means 130, which is configured, when the detection value obtained by the toner supply detection sensor 119 is not changed by a normal amount after supplying the predetermined amount of toner to the developing device 2, to change the toner supply amount, according to the variation of the detection value of the toner supply detection sensor 119. <P>COPYRIGHT: (C)2011,JPO&INPIT |
