| 摘要 |
PURPOSE: To stabilize triboelectrification characteristics of the developer without requiring any mechanical preconditioning by specifying the triboelectrification products of developer compositions. CONSTITUTION: In this method, the triboelectrification product of a first developer composition contg. first toner particles and unused carrier particles is measured and by using the first developer composition for electrophotographic image forming cycles of >=5,000, the first developer composition is formed into an aged first developer composition having about 10 to 200%.μC/g triboelectrification product and then, the triboelectrification product of this composition is measured. A second developer composition contg. second toner particles and unused carrier particles is formed and charged into a electrophotographic image forming device and with the decrease in amount of the second toner particles due to the image development, the first toner particles of the aged first developer composition are added to the device. The triboelectrification products of the first and second developer compositions are adjusted so that they are unequal to each other on condition that each of them is about 10 to 200%.μC/g. Thus, any mechanical preconditioning is not required. |
