| 摘要 |
PURPOSE:To obtain an excellent developed image with high developing efficiency by forming a magnetic brush in such a manner that magnetic particles exist in a specific amt. in a developing region and developing the latent image while the nonmagnetic toner holding the pulverous particles of another compd. existing in the direction opposite from the toner in the developing region is moved back and forth. CONSTITUTION:The compd. A has the electrostatic charge characteristic reverse from the toner and has the role to provide the intrinsic electrostatic charge to the toner and the compd. B controls the excess electrostatic charge with the toner and the magnetic particles to provide a release effect in order to process the magnetic particles. The compd. C which acts in the same manner as the compd. A in terms of electrostatic charge is held as the pulverous particles in the toner, then the pulverous particles of the compd. parts slightly from the toner in certain environment and plays the role of intensifying the electrostatic charge of the toner. The coating amt. of the magnetic particles on the sleeve surface on the down stream of a nonmagnetic blade 24 is kept at a small amt. of about 5-100mg/cm<2> in order to make substantial use of both the magnetic brush and the sleeve 22 surface. The developing brush 51 is held in the finely but vigorously oscillated state by an alternating magnetic field, by which the toner is made easily removable from the brush 51 and easily suppliable to a latent image holding body 3. The image density is improved as well. |
