Abstract: Magnetic brush developer apparatus which alleviates any developer material starvation in the area of contact with a charge pattern-bearing member. Such apparatus develops an electrostatic charge pattern on a member by contacting the member with developer material, including magnetic particles, transported toward and away from the charge pattern-bearing member by an applicator member. The transported developer material is magnetically agitated in the area of contact with the charge pattern-bearing member in a direction which includes at least a component perpendicular to the transport direction, whereby intermixing of the developer material in such contact area is substantially improved to reduce any propensity toward toner starvation and the developed image defects resulting from such starvation.

Abstract: An electrographic development station is disclosed which includes three magnetic brushes which sequentially apply toner to an electrostatic image on a moving photoconductor. The two upstream brushes rotate counter-current with respect to the movement of the photoconductor and have magnetic fields which overlap so that developer is carried from one brush to the other. The third magnetic brush rotates co-current with regard to such photoconductor movement. The two counter-current brushes apply a large quantity of toner to an electrostatic image on the photoconductor and the co-current brush applies a sufficient amount of toner to develop any incompletely developed portions of an electrostatic image.