Browse Prior Art Database

Original Publication Date: 1978-Aug-31
Included in the Prior Art Database: 2004-Mar-31

Publishing Venue

Xerox Disclosure Journal


A magnetic brush-type development system may be employed in an electrophotographic printing machine. In one embodiment of the magnetic brush developer roller as shown in Figure 1, donor roll 38 includes a non-magnetic tubular member 50. Tubular member 50 includes a plurality of depressed regions 52 therein, Depressed regions 52 are a plurality of grooves extending about the circumferential surface of tubular member 50, Grooves 52 are substantially, equally spaced from one another in a direction extending along the longitudinal axis of tubular member 50. Tubular member 50 is interfit concen-trically over magnetic member 54. A shaft 56 is concen-trically mounted within tubular member 50 and serves as a support for magnetic member 54. Motor 58 is coupled to shaft 56 and rotates magnetic member 54 relative to tubular member 50, Tubular member 50 remains substantially stationary. Grooves 52 of tubular member 50 are oriented so as to be substantially parallel to the direction of rotation of the photoconductive drum. These grooves vary the spacing between tubular member 50 and the photoconductive surface to produce tonal graduations in the copy being reproduced.