| 摘要 |
<p>PURPOSE:To obtain a sufficient image density, to lessen fogging and to obtain good images by forming conductive magnetic carriers of substantially spherical carriers having specific saturation magnetization and stably developing only the insulating toners. CONSTITUTION:The images are formed by bringing a developer into contact with the surface of a photosensitive body 3 by a developing sleeve 1 internally arranged with a magnetic member and simultaneously subjecting the photosensitive body 3 to image exposing from the inside. This developer is prepd. by mixing the conductive magnetic carriers and the insulating toners. The conductive magnetic carriers are the substantially spherical carriers having 15 to 30mum average particle sizes and 50emu/g saturation magnetization at 10KOe external magnetic field. Resin carriers formed by dispersing magnetic powder into a resin are applied as an example of the conductive magnetic carriers. The resin carriers are obtd. by a so-called spray drying method of dispersing magnetic powder and a binder resin into a solvent, then spraying the dispersion into hot atm. air and drying the dispersion and is also obtd. by dispersing the magnetic powder into a resin monomer and subjecting the dispersion to suspension polymn.</p> |
