| 摘要 |
PROBLEM TO BE SOLVED: To discharge deteriorated toner and identify a source of image density change, while reducing toner consumption.SOLUTION: A discharge control section controls a charging section, an exposure section, and a developing section, to form a pattern on a photoreceptor drum, primarily transfers the pattern to an intermediate transfer belt, and forcibly discharges deteriorated toner stored in the developing section. The discharge control section detects density-change period of the pattern, to be used for identifying a source of the density change. A read sensor detects density of the pattern. An identifying section analyzes a result detected by the read sensor, to determine density-change period in the pattern, and identifies a rotating body corresponding to the determined period, from among rotating bodies, such as the photoreceptor drum, the charging section, the developing section, and a primary transfer section, as a source of the density change.SELECTED DRAWING: Figure 6 |
