Original Publication Date: 1983-Oct-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
In an electrophotographic printing machine, the development apparatus frequently employs a two-compenent developer material. The developer material comprises toner particles adhering triboelectrically to carrier granules. Frequently, the toner particles contained within the development system escape therefrom resulting in contamination of the printing machine. The development system includes a magnetic brush developer roller which transports developer material closely adjacent to the photoconductive surface. A metering blade regulates the thickness of the layer of developer material adhering to the developer roll. It has been found that a fairly thick layer of toner particles forms on the metering blade. This accumulation of toner particles on the metering blade provides a source, in at least part, of toner particles which escape from the development system resulting in contamination of the surrounding subassemblies within the printing machine. As shown in Figure 1, development system 38 includes a housing 58 defining a chamber 60 for storing a supply of developer material therein. Developer roller 40 is mounted in chamber 60 of housing 58 and disposed adjacent thereto. Developer roller 40 advances the developer material into contact with the electrostatic latent image recorded on belt 10. Metering blade 62 regulates the thickness of the developer pile height on developer roller 40. The developer material rotates in the direction of arrow 64. The thickness of the layer of developer material adhering to developer roller 40 is suitably adjusted to regulate the compressed pile height of the developer material to the desired level. Metering blade 62 extends in a longitudinal direction across the width of developer roller 40 so as to provide a substantially uniform gap controlling the quantity of material being moved into the development zone. Developer roller 40 includes a non-magnetic tubular member 66 having an elongated magnet 68 disposed interiorly thereof and spaced therefrom.