Development of the Image in a Photocopying Machine

The mathematical problem to
compute the development of
the toner image from an
electrostatic one during
photocopying has been studied
from the point of view of
existence and uniqueness by
Friedman and coworkers. Here
we formulate the problem as
an integral equation. We use
the Green's function involved
to solve the problem exactly
at the initial instant and
approximately by numerical
solution of the equation at
later times.