| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device capable of effectively preventing a lots of electrification defective toner from being stuck on a developing roller after the toner replenishing, and restraining the toner whose electrification property is poor from being stored in the developing chamber. SOLUTION: In the case the printing count valve is not O (S6:NO), the bias voltage of the constant voltage is applied on the toner feeding roller by a high voltage power source circuit part (S14). Next, the printing is started (S15). Then, whether a photosensitive drum is rotated for a printing sheet portion or not is detected by a timer of a control circuit inside, when a rotation for a printing one sheet portion (S16:YES), the printing count value is reduced by 1 (S18), the cumulative printing sheet value is increased by 1, and stored stored again in an EEPROM(electrically erasable programmable ROM) (S9). Next, the printing is not completed (S10:NO), the residual toner quantity of the toner cartridge is detected (S4), and the printing operation is continued. |
