Abstract: This is an electrophotographic marking system that effectively cleans residual toner and toner additives from the surface of a photoreceptor. This cleaning process reduces ghosting problems that had been encountered in final copies produced by electrophotographic systems such as in copiers, printers and duplicators. This cleaning is accomplished by expedients such as increasing a cleaning brush bias, and by increasing the surface area of cleaning brushes used in the system. In addition, the development process is desensitized to the development of ghosting. This desensitizing is accomplished by expedients such as increasing the gap between the development roll and the photoreceptor and by reducing the AC development electrical bias.

Abstract: A development subsystem is used to develop developer having semiconductive carrier particles and toner particles. The development subsystem includes a developer housing, for retaining a quantity of developer having semiconductive carrier particles and toner particles, a first magnetic roll having a stationary core with at least one magnet and a sleeve that rotates about the stationary core of the first magnetic roll, a second magnetic roll having a stationary core with at least one magnet and a sleeve that rotates about the stationary core of the second magnetic roll, and a motor coupled to the first and the second magnetic rolls to drive the rotating sleeves of the first and the second magnetic rolls in a direction that is against the direction of a photoreceptor that rotates in proximity to the first and the second magnetic rolls. The first and the second magnetic rolls carry semiconductive carrier particles and toner particles through a development zone formed by the first and the second magnetic rolls.

Abstract: A developer includes black toner particles and carrier particles, the black toner particles including at least one binder, at least one black colorant and one or more external additives, wherein the toner particles comprise from about 7 to about 15 pph of the developer, and wherein the toner particles exhibit a triboelectric charge of from about ?25 to about ?50 ?C/g at toner particle concentrations of about 7 to about 15 pph of the developer. The developer is ideally suited for use in a high speed (greater than 100 prints per minute) semiconductive magnetic brush development apparatus. Preferably, the black toner particles include a styrene acrylate binder, and the external additives include from about 1.3 to about 2.1% by weight of the toner particles of a first silica having an average particle size of from about 35 to about 45 nm, from about 0.5 to about 1.0% by weight of the toner particles of a second silica having an average particle size of from about 135 to about 160 nm, and from about 0.

Abstract: An apparatus for removing charged particles from a surface, the surface being capable of movement, including: a conductive brush in contact with the surface, the conductive brush having a first region thereof having a first polarity and a second region having a second polarity; the conductive brush includes a core and conductive fibers attached thereto, the core being electrically segmented into the first region and the second region.