| 摘要 |
PROBLEM TO BE SOLVED: To prevent toner from being scattered from a developer carrier without necessitating excess torque and to obtain excellent sealing property by making the potential of a magnetic seal arranged outside the developing area of a developer carrier have the same polarity as a developer carrier and larger than the potential of the developer carrier. SOLUTION: The magnetic seal 100 is provided at a part corresponding to a toner non-coating area, is a magnet constituted of six poles and made of ferrite and is arranged through a gap being 0.5 mm from a developing sleeve 240, and a magnetic seal showing about 200 gauss on the surface of the sleeve 240 is selected as the seal 100. The high voltage power source 101 of the image forming device supplies Vs to the sleeve 240 and Vm to the seal 100. Voltage obtained by superposing AC voltage same as Vs on DC voltage being -5.50 V larger than DC voltage of Vs is applied as Vm. Thus, the toner generating electric field in a gap between the sleeve 240 and the seal 100 does not fall off. |
