Mixing Property and Toner Concentration Control of Two Component Developer

Abstract

Mixing Properties of ferrite carrier and small toner particles in a developing unit have been investigated using a newly developed toner concentration sensor with an inductance coil. A measurement equipment with the sensor can measure a toner concentration of two component developer at a sensitivity of 0.01 %. Time responses of the toner concentration in the developing unit are measured precisely by the sensor when toner is consumed and fresh toner is supplied impulsively. From these measurements of time response, it is found that the mixing property of fresh toner supplied into the developer mainly depends on a charging process of the fresh toner. Using the response property of toner mixture, a toner supply rate, and a toner consumption rate, time variation of toner concentration in the developer unit can be simulated. Calculated results of toner concentration based on the simulation are consistent with experimental results.