Patent ID: 7756449

Claim:
An electrophotographic printing apparatus, comprising: an image forming member having a surface on which a latent electrostatic image can be formed; a developer operable to deposit onto the surface of the image-forming member a layer of ink, the ink comprising charged ink particles and a carrier medium; a supply conduit connecting an ink tank to the developer and an exit conduit connecting the ink tank to the developer, wherein ink is supplied from the developer to the ink tank through the exit conduit, and the supply conduit, the developer, and the exit conduit define a flow patch between the developer and the ink tank; and a separator connectable to the flow path to receive from the flow path unused ink supplied from the developer, operable to extract the carrier medium from the unused ink received from the flow path, and connectable to the flow path to supply the extracted carrier medium to the flow path; wherein the separator comprises an electrode and a blade, the electrode being electrically chargeable to generate an electric field the causes separation of the charged ink particles from the carrier medium in the unused ink received from the flow path by attracting the charged ink particles to a surface, and the blade being operable to remove charged ink particles that are attracted to the surface from the surface.