| 摘要 |
PROBLEM TO BE SOLVED: To omit a toner density sensor in a development tank while suppressing a decrease in precision of toner empty detection.SOLUTION: An image formation apparatus comprises a toner cartridge, a development tank, a control unit, and an operation display unit. The control unit forms a test toner image at a timing when toner supply from a toner cartridge to the development tank would exert no influence on density and at a timing when toner supply would exert an influence on the density, and then determines that a toner cartridge is not empty when a density difference of both test toner images is equal to or larger than a threshold and that the toner cartridge is empty when the density difference is less than the threshold. When it is determined that the toner cartridge is empty, the operation display unit reports the fact.SELECTED DRAWING: Figure 7 |
