| 摘要 |
PROBLEM TO BE SOLVED: To reduce surface staining caused by the faulty electrification of image forming substance by constituting a reference value correction means so that the stepwise correction of a reference value by which the reference value gradually approaches to a correction value may be executed. SOLUTION: A control part 10 does not ordinarily execute correction that a correction amount ΔVTref is merely added to the reference value VTref set till the previous correction but executes the stepwise correction of the reference value in reference value correction control. The stepwise correction of the reference value is the correction of the reference value that a numerical value(division correction amount) smaller than the correction amount ΔVTref is gradually added to the reference value VTref so that the final addition amount to the reference value VTref may be the correction amount ΔVTref. Thus, toner replenishment control that toner is supplied little by little is performed and time taken till completely electrifying the toner is made shorter than the case that the toner is supplied at a stretch. |
