CALCULATION OF ELECTROSTATIC-FIELD IN AN ELECTROPHOTOGRAPHIC DEVELOPMENT ZONE

It is important to measure the electrostatic field in the electrophotographic development zone in designing copying machines. Since this zone is of a complex structure, no measurement method has been established and, hence, it is difficult to analyze this zone. In this paper, new equations to obtain the electrostatic potential and field in the development zone are obtained. In formulating the equations, it is assumed that the electrophotographic development zone was composed of four layers, 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 chart was assumed to be present on the photosensitive surface. In addition, an image charge which satisfies the boundary condition was taken into account. Using this method, the electrostatic potential and electric field distributions in the development zone could be evaluated when a square wave-shaped charge with an arbitrary spread and charge density distribution was applied. Of course, this method could be applied to the case where the charge had an arbitrary shape. Moreover, this method is more precise than the finite element method. In addition, the software for this method can easily be developed and the calculation time is extremely short.