| 摘要 |
PURPOSE: To simply switch one developing unit to the two-component development mode and the one-component development mode and provide an image utilizing the features of respective development systems. CONSTITUTION: This developing unit is provided with a developing sleeve 43, a magnet body 42 having a magnetic pole section N2 and a magnetic poleless section 42a inserted into the developing sleeve 43, a feed roller 46 rotated against the developing sleeve 43, a switch 107 and a power source 109 switching the developing sleeve 43 and the feed roller 46 to the potential difference state or the unipotential state, a switching lever 100 and a solenoid 103 switching the magnetic pole position of the magnet body 42, and a control device 111 switching the switch 107 and the solenoid 103 based on the two-component development mode feeding a developer constituted of a toner and a carrier to the developing sleeve 43 via the magnetic force of the magnetic pole section N2 or the one-component development mode feeding only the toner to the developing sleeve 43 based on the potential difference. |
