Browse Prior Art Database

Original Publication Date: 1980-Jun-30
Included in the Prior Art Database: 2004-Apr-02

Publishing Venue

Xerox Disclosure Journal


In an electrophotographic printing machine, the development system requires additions of toner particles thereto. Additional toner particles may be furnished to the development system by a toner dispensing system. Preferably, the toner dispensing system furnishes toner particles over an extended area in an even fashion. This may be achieved by introducing toner into a cylinder through large cutouts in a foam roll sleeve and large holes in a cylindrical screen. Once the toner is in the cylinder, helical vanes attached to the inner surface of the cylinder move the toner laterally along the inside of the cylinder. The helical vanes have the appropriate pitch direction and physical size to advance the toner in both directions. This counteracts the effect of gravity and prevents overfilling of the cylinder. Since the cylinder is kept in a partly filled state, the toner is made turbulent by the tumbling action thereof. An even distribution of toner is provided by the self-leveling effect of gravity along the length of the cylinder. The even toner level along the length of the cylinder facilitates uniform toner dispensing across any development housing. Since the cylinder is made from a screened material, toner is distributed through the wall onto the foam shield. Holes in the shield permit the toner to be dispensed in specified areas. The vanes in the screen cylinder are preferably made from two spiral wire coils extending along the length thereof. One of the coils has a clockwise pitch while the other has a counterclockwise pitch. Toner agitation and translation in the cylinder is aided by partially filling the cylinder with large, loose beads.