Our proposed model for toner tribo-charging can well explain the dependence of toner charge to mass ratio q/m of two-component developer on toner concentration. According to the model, there are three types in dependence of toner charge to mass ratio on toner concentration. Type I is constant toner charge to mass ratio and Type II is decreasing toner charge to mass ratio with increasing toner concentration. Type III shows the Type I and Type II mixed characteristics. These dependence of toner charge to mass ratio on toner concentration are affected by toner and carrier properties. However, we have scarce information of carrier side to toner tribo-charging. We try the characterization of commercial carriers. Carrier charge to mass ratio, Qc/Mc to metal plate having different work function is measured. It is found that there are well defined the relationship between carrier charge to mass ratio and type of toner concentration dependence of toner charge to mass ratio.
Masaaki Aoike, Won-Sup Lee, Makoto Omodani, Yasusuke Takahashi, "Carrier Characterization and Related Toner Charging Property in Two Component Developers" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP14), 1998, pp 386 - 389, https://doi.org/10.2352/ISSN.2169-4451.1998.14.1.art00013_2