Toner Surface-Charge Density in Two-Component Development System.

— Effect of Toner Particle Size —

Abstract

Triboelectric-charging and the two-component development system with insulative carrier have been studied by varying the toner surface-area median size (d₅₀) from 6.8 to 13.5 μm and the carrier surface-area median size (D₅₀) from 43 to 106 μm.
It has been found that the development efficiency is determined by surface-charge density (q/s_t) of the toner particles independent of the toner size (d₅₀), rather than by the charge-to-mass ratio (q/m) as formulated by Schein and by the other workers, and that triboelectric-charging is should more likely be described by q/s_t as a function of surface area ratio of toner to carrier (ns_t/s_c), as suggested by Kurita, rather than by q/m as a function of mixing-ratio (X) of toner to carrier.
The developed toner-mass per unit area on a photoreceptor (M/A) has been described by a formula, M/A∝[α-β(q/s_t)] (where α and β are numerical constants), in the experimental range of q/s_t from 3.5 to 7.0 nC/cm². The triboelectric-charging has been discussed from a view of phenomena entirely concerned with the surface of toner and insulative carrier particles.