Patent ID: 7343121

Claim:
A method for controlling the charge on two-component particulate developer, including particulate toner, in a development station of an electrographic reproduction apparatus, comprising the step of: selectively supplying a quantity of liquid charge control agent necessary to adjust the charge-to-mass ratio of the particulate toner to a desirable range or value by injecting a calculated amount of liquid charge control agent into the development station wherein said liquid charge control agent comprises one of an alkane hydrocarbon, silicone liquid and a water-based liquid using at least two separably controllable injectors comprising one injector for water and another injector for the alkane hydrocarbon or silicone liquid; and adjusting one or more process control parameters of the electrographic process to a desirable range or value wherein the supply a quantity of charge control agent is selected to adjust one or more of Vzero, toning bias, development potential, Vgrid, exposure intensity, or exposure time to a desirable range or value.