| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device where resistance value of magnetic carrier of developer of a two component developing device is higher compared to that of magnetic particles for electrifying of a magnetic brush contact electrifying device, deterioration of electrifying function in electrification of the magnetic brush can be prevented even when the magnetic carrier is mixed into the magnetic brush contact electrifying device and a good image without any fogging or unevenness in an image, etc., can be obtained over a long period of time even when a cleanerless system with a developing simultaneous cleaning method is adapted. SOLUTION: In this device, concerning volume resistivity Rc and average particle diameter lc of the magnetic particles of the magnetic brush electrifying device and volume resistivity Rv and average particle diameter 1v of the magnetic carrier of 2 component developer, when A=log Rv/Rc, B=lv/lc, α=1/5.B/A.lv, β=B/A.lv the percentage C (%) of the volume of the magnetic particles that have a particle diameter of α to β in the magnetic particles as a whole is >=5% when A/B is >=2. |
