| 摘要 |
PURPOSE:To enhance mobility of a toner under environments of high temperature and high humidity lowering the fluidity of a developer and to prevent deterioration of image quality, such as lowering of image density and image thinning by coating a carrier with a combination of a fluororesin and a styrene type resin and applying mechanical treatment to the carrier in the range of almost not changing triboelectrification between the toner and the carrier. CONSTITUTION:The mechanical treatment is applied to the carrier coated with a combination of the fluororesin and the styrene type resin in the range of 0.9 - 1.1 Q muc/g, where Q is a triboelectrification amount of the toner given by the carrier, that is, in the range of almost not changing the amount. It is preferred to use a machine giving small impact to the carrier particles, and a vessel fixed screw mixer is preferably used. A screw stirrer 1 rotates together with a swing arm 2 along the inside wall of an inverted conical hopper and stirs and mixes a developer powder contained in the hopper, as shown in the figure in order to mechanically treat the carrier, thus permitting the mobility of the toner to be enhanced under environments of high temperature and high humidity lowering the fluidity of the developer, and lowering of image quality, such as lack of image density and thinning of an image, to be prevented. |
