| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus including a trickle developing apparatus, configured to allow efficient replacement of developer in the developing apparatus if necessary.SOLUTION: When images are formed successively on a predetermined number of sheets or more at a printing rate lower than a predetermined rate, or an instruction is issued from a user, the amount of developer to be supplied per unit time by a supply screw 52 of a developer hopper 5 is larger than the amount of developer to be conveyed per unit time by a second conveyance screw 26. An outlet 274 of a developing apparatus 2 is preferably arranged downstream of a second communication port 272 in a developer conveyance direction of a first conveyance screw 25. A supply opening 273 is preferably arranged upstream of the second communication port 272 in the developer conveyance direction of the second conveyance screw 26. |
