Magnetically biased development of magnetographic images

The effect of magnetic bias fields on magnetographic development is studied. An analytical model of image field and associated force on toner particles is modified to incorporate bias fields of either direct or reverse polarity with respect to the dots magnetization. Using simple series expansions derived from the model, the main mechanisms of biased development are first identified. Based on the full model, 3-D computer simulations of the particles equilibrium on the imaged media, while exposed to bias fields of various intensity and polarity, are then provided and shown to reproduce quite reliably the real observed behavior.