| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique capable of shortening the detection time without deteriorating detection accuracy in detection of a surface potential of a photoreceptor.SOLUTION: A voltage application member applies voltages to an image carrier with at least three application voltage values V, V, Vbeing voltage values larger than a break-down voltage value, having mutually-different magnitudes and having at least one value with the current flow direction reverse to the other values. A potential detection part obtains a relationship in a discharge region in a relationship between the application voltage values and detection current values on the basis of at least the three application voltage values V, V, Vand at least the three detection current values I, I, Idetected by a current detection part with respect to at least the three application voltage values V, V, V, and obtains a voltage value Vin which the detection current value becomes zero on the basis of the relationship in the discharge region.SELECTED DRAWING: Figure 1 |
