| 摘要 |
<p>PURPOSE: To utilize a polymerized toner over a wide concn. range, to attain high image density and to prevent fogging by using a nearly spherical magnetic carrier having fine surface ruggedness and a specified median particle diameter and a spherical toner as constituents. CONSTITUTION: This developer consists of a nearly spherical magnetic carrier having fine surface ruggedness and 60-100μm median particle diameter and a spherical toner having 5-8μm median particle diameter. The spherical toner means a polymerized toner and a toner obtd. by utilizing a spray drying method. In order to use the spherical toner over a wide concn. range, the nearly spherical magnetic carrier having fine surface ruggedness is used. Since the carrier has an increased surface area because of the fine surface ruggedness, it has such a degree of margin as not to cause trouble to the electrostatic charge of the toner even when fine powder contained in the toner sticks somewhat to the surface of the carrier. The carrier has high flowability because of its nearly spherical shape, high efficiency of stirring with the toner is attained and fogging is suppressed.</p> |
