| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of determining the state of deterioration of developer by a simple method.SOLUTION: A detection unit 67 is provided opposite a housing. The detection unit 67 detects pulse signals sequentially detected according to the oscillatory frequency of developer as density-related values at the opposite position. A determination unit 95 determines the state of deterioration of the developer on the basis of the pulse signals detected by the detection unit 67. When determining that the developer is deteriorated, the determination unit 95 determines whether new toner is supplied to a developing unit 60 or toner is discharged from the developing unit 60 on the basis of the determination of whether or not the density of toner will be within an acceptable range even if new toner is supplied to the housing, and the determination that toner can be supplied because the density of toner will be within the acceptable range as a result of decrease of toner due to future printing.SELECTED DRAWING: Figure 6 |
