| 摘要 |
PURPOSE:To continuously obtain a large number of copied images of high density and high quality by combining utilization of developer with resin coated ferrite carrier provided with a specific magnetic characteristic and a method of a narrow doctor gap. CONSTITUTION:A magnetic brush is formed by sticking developer 7 consisting of the resin coated ferrite carrier with saturation magnetization of 40 to 60emu/g, residue magnetization of 3 to 13emu/g, and coercive force of 5 to 250e and toner on an outer periphery surface of a developing sleeve 4 with magnetic force and napping of the magnetic brush is restricted by setting the doctor gap at 0.3 to 0.8mm. Napping is formed even with a narrow doctor gap a by weakening the sticking of carrier to the magnetic sleeve 4 by having such a magnetic characteristic as described above imparted to the resin coated ferrite carrier. Thus by utilizing the two component type developer with which good napping and an appropriate developing function can be obtained, the image of high density and high quality can be obtained in copying of a great number of pieces. |
