Xerographic development apparatus and process

Claim 2

Apparatus as described in claim 1 wherein said first and second brushes are comprised of synthetic or natural furs having coated thereon a metal selected from the group consisting of a Group VIa metal, a group VIII metal, a Group Ib metal, a Group IIb metal, aluminum and mixtures thereof.

Claim 3

Apparatus as described in claim 1 wherein at least one of said brushes is in the form of a cylinder.

Claim 4

Apparatus as described in claim 1 wherein at least one of said brushes is in the form of a continuous belt.

Claim 5

Apparatus as described in claim 1 wherein said means for alternately contacting one of said brushes comprises selectively movable guide means for guiding said element into contact with at least one of said brushes.

Claim 6

Apparatus for applying electroscopic toner material to an element bearing an electrostatic charge pattern, said apparatus comprising first and second movable fur brushes capable of contacting said element, means for applying toner to said brushes, means for selectively conveying said element into contact with at least one of said brushes whereby said toner is attracted from said brush to the element in accordance with the charge pattern, said brushes comprising synthetic or natural furs having coated on the individual filaments thereof a thin layer of an electrically conductive metal imparting to said brushes a humidity independent electrical conductivity, said first brush having an electrical resistivity of greater than about 108 ohms/square and said second brush having an electrical resistivity of less than about 104 ohms/square.

Claim 7

Apparatus as described in claim 7 including means for sequentially guiding said element into contact with both of said brushes whereby toner is attracted to said element from both brushes.

Claim 8

A process for developing electrostatic charge patterns comprising the steps of: a. forming an electrostatic charge pattern on an element, b. applying electroscopic toner material to first and second movable fur brushes each comprised of a support bearing individual flexible filaments which are coated with a thin layer of an electrically conductive metal, one of said brushes having an electrical resistivity of greater than 108 ohms per square and the other having an electrical resistivity of less than about 104 ohms per square, and c. sequentially contacting said charge pattern with said first and second brushes whereby said toner is deposited in accordance with said charge pattern to give both fringing and solid area development.

Claim 9

A process as described in claim 9 wherein the fur brushes are comprised of synthetic or natural furs having coated on the individual filaments thereof a metal selected from the group consisting of a Group VIa metal, a Group VIII metal, a Group Ib metal, a Group IIb metal, aluminum and combinations thereof.