CALCULATION OF ELECTROSTATIC-FIELD IN AN ELECTROPHOTOGRAPHIC DEVELOPMENT ZONE

It is important to measure the electrostatic field in the electrophoto graphic development zone in designing copying machines. Since this zon e is of a complex structure, no measurement method has been establishe d and, hence, it is difficult to analyze this zone. In this paper, new equations to obtain the electrostatic potential and field in the deve lopment zone are obtained. In formulating the equations, it is assumed that the electrophotographic development zone was composed of four la yers, that is, an electrically conductive substrate, a photosensitive layer, a development space, and a development electrode. For analysis, a charge distribution having a figure similar to a resolution test ch art was assumed to be present on the photosensitive surface. In additi on, an image charge which satisfies the boundary condition was taken i nto account. Using this method, the electrostatic potential and electr ic field distributions in the development zone could be evaluated when a square wave-shaped charge with an arbitrary spread and charge densi ty distribution was applied. Of course, this method could be applied t o the case where the charge had an arbitrary shape. Moreover, this met hod is more precise than the finite element method. In addition, the s oftware for this method can easily be developed and the calculation ti me is extremely short.