| 摘要 |
PURPOSE:To obtain always good images by specifying the residual magnetization of a magnetic carrier after passage through 1,000 oersted magnetic field. CONSTITUTION:The residual magnetization of the magnetic carrier after the passage through 1,000 oersted magnetic field is confined to 0.3, more preferably <=0.2emu/g. The adhesion of magnetic particles to a photosensitive body, therefore, increases because of the low residual magnetization on the downstream side of the developing region existing in the position apart from the main magnetic pole, i.e. the position where the magnetic force from a magnet roll weakens. The magnetic particles are liable to part from a sleeve between S and N poles and the triboelectrostatic charge is liable to be generated by the agitation with a toner if the residual magnetization is small. Since the magnetic particles have the high electrostatic charge quantity in this way, the particles are liable to adhere to the high-potential part of the photosensitive body. The toner concn. in the developer is consequently automatically maintained in a prescribed range and always the good images are obtd. |
