Browse Prior Art Database

Original Publication Date: 1995-Jun-30
Included in the Prior Art Database: 2004-Apr-07

Publishing Venue

Xerox Disclosure Journal


A developer unit includes a magnetic brush developer roller having a developer auger for transporting developer material. The developer auger advances the developer material in one direction. A transport auger positioned adjacent the developer auger advances the developer material in an opposite direction. Developer material at one end moves from the transport auger to the developer auger. Developer material, at the other end, moves from the developer auger to the transport auger. In this way, the developer material moves in a recirculating path. A center board is interposed between the transport auger and the developer auger. An excess of developer material is maintained in the developer auger. This excess of developer material spills over the center board from the developer auger into the transport auger. The developer auger always runs full. In order to achieve this, the efficiency of the transport auger varies so that it becomes less efficient in the direction of developer material travel. This enables a small but constant amount of developer material to fall over the center board from the developer auger into the transport auger along the entire length of the developer auger. The level of developer material in the transport auger is below the center board level at all times. This is achieved by having the transport auger channel somewhat larger than the channel in the developer auger. Alternatively, it may be achieved by having the developer auger more efficient than the transport auger. In this way, a small amount of developer material falls over the center board all along the length thereof. The advantage is that when the housing is tipped slightly end to end the resulting efficiency change in the augers will at first merely change the distribution of where the excess material in the developer auger is moved onto the transport auger. The level of the developer material will still be exactly at the center board height. This reduces the developer unit sensitivity to housing tilt.