Development of the visual image in electrophotography

The development of the visual image in an electrophotographic copying machine is studied on basis of a mathematical model proposed by Spence. The resulting moving boundary problem is solved in time steps. An electrostatic problem, which has to be treated at each step, is formulated as an integral equation, which is solved numerically. The solution is found for various values of the parameters involved and the dependence of the solution on them is discussed.