Magnetic toner apparatus
AssigneeSperry Corporation
InventorJames B. Thaxter
Life of this patent
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Abstract
Magnetic apparatus for dispensing toner of an electrophoretic printer having a hopper fed magnetic brush in conjunction with an active or passive magnetic backing plate is disclosed for transferring a uniform layer of toner to a transfer surface or belt for high speed printing purposes. The magnetic apparatus includes a magnetic roller having an inner magnetic surface and an outer cylindrical surface disposed in magnetic relationship to the toner and opposite one side of the transfer surface. The apparatus further includes a magnetic backing plate disposed opposite the other side of the transfer surface and juxtaposed to said magnetic roller for transferring the toner to the transfer surface.
Claims8
An improved electrophoretic printer of the type having a recipient sheet, a printhead, a supply of toner, and a transfer surface having first and second sides, for conveying the toner to the printhead for transferring the toner to the recipient sheet to form an image thereon, wherein the improvement comprises:
- a magnetic roller disposed in magnetic relationship to the supply of toner and opposite the first side of the transfer surface, having an inner magnetic surface and outer cylindrical shell, for generating magnetic field gradients and magnetically attracting the toner to the outer cylindrical shell;
- and
- a high permeability backing plate disposed opposite the second side of the transfer surface and aligned with the magnetic roller cooperating therewith for modifying the magnetic field gradients by magnetization induced in the high permeability backing plate having a selectively profiled surface to produce selectively profiled gradients and for transferring the toner from the roller to the transfer surface in a controlled, uniform thickness.
Dependencies are inferred from the claim text.