| 摘要 |
PURPOSE:To extend a range in which the concn. of a toner is controlled and to form an image of high quality by combining an inorg. carrier having certain saturation magnetization and a particle size each in a specified range with a toner having a particle size and certain saturation magnetization each in a specified range, specified volume resistivity or above and a specified extent of electrostatic charge or above. CONSTITUTION:A magnetic carrier having 40-220emu/g saturation magnetization and 5-200mum particle size such as iron powder is combined with a magnetic toner contg. resin, magnetic powder and an electrostatic charge controller and having 5-40mum particle size, >=10OMEGA.cm volume resistivity, 3-40emu/g saturation magnetization and >=¦10¦muc/g extent of electrostatic charge to prepare a developer. The saturation magnetization of the carrier in the developer is 2- 35 times that of the magnetic toner, and the particle size of the carrier is about 1-about 2.5 times that of the magnetic toner. By using the developer, an image of high quality is formed even when a range in which the concn. of the toner is controlled is extended, and the sticking of the carrier to a photosensitive drum is prevented. |
