| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus immediately detecting exhaustion of toner to be supplied to a developing device, and preventing carrier from being deposited on a photoreceptor due to a reduction in toner concentration.SOLUTION: The image forming apparatus 100 includes: a developing device 2 including a developing tank 111, first and second conveying members 112 and 113, a developing roller 114 and a toner replenishing port 115a for guiding the replenished toner into the developing tank 111; a toner replenishing device 22 for replenishing the toner to the developing device 2; a toner replenishment detecting sensor 119 for detecting the toner replenishment into the developing tank 111; a toner concentration control means for giving an instruction to replenish the toner when the toner concentration becomes less than a predetermined value; and a toner-exhaustion detecting means for determining the toner exhaustion in the toner replenishing device 22. The toner replenishment detecting sensor 119 is disposed in the vicinity of the toner replenishing port 115a. |
