Patent ID: 8224195

Claim:
A method to control a development process in an electrographic process and electrographic printer or copier, comprising the steps of: with at least one developer station inking a latent image on an intermediate carrier with toner of a predetermined color, the toner being extracted from a mixture made up of toner and carrier particles, and wherein fresh toner is supplied to the mixture; determining a characteristic value D for a status of the mixture from a model calculation in which a toner exchange rate b with which fresh toner is supplied to the mixture per time increment, and an operating aging rate a which indicates a proportion of toner that remains in the developer station and is thereby damaged by re-use per time increment of operation of the developer station, are linked; at least one of monitoring, controlling, or regulating the development process, dependent on the characteristic value D; and in which the characteristic value D is calculated iteratively according to a relationship P i =a i −( a i +b i )· D i D i+1 =D i +P i ·ΔT wherein D i is the characteristic value D at an actual time increment i and D i+1 is the characteristic value D at a next time increment i +1, i is a running variable for the time increments, P i is an auxiliary variable, a i is the operating aging rate in 1/s, b i is the exchange rate in 1/s and ΔT is the time increment size in s.