Transfer System for an Electrophotographic Device
AssigneeLexmark International, Inc.
InventorsChristopher Michael Bennett, Gerald Floyd Davis, Kurt Daniel Lambert, Niko Jay Murrell, Julie Ann Gordon Whitney
Life of this patent
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Abstract
A device for transferring images from an image donating member to an image receiving medium comprises a substrate, at least two electrodes disposed on the substrate, and at least one layer of coating disposed on the substrate having an outer surface for forming a nip region with the image donating member. The at least two electrodes are controllable to produce an electric field and control a position thereof at the nip region to allow transfer of an image from the image donating member to the image receiving medium in an image transfer operation.
Claims20
A device for transferring images from an image donating member to an image receiving medium, comprising:
- a substrate;
- at least three electrodes disposed on the substrate, including a center electrode and at least two guard electrodes disposed at opposed sides of the center electrode;
- and
- at least one coating layer disposed on the at least three electrodes and having an outer surface for forming a nip region with the image donating member;
- wherein the at least two guard electrodes comprise a first guard electrode and a second guard electrode, and wherein a distance between the first guard electrode and the center electrode is greater than a distance between the center electrode and the second guard electrode.
A toner transfer system, comprising:
- a donating member for donating toner;
- a transfer member including a substrate, at least three electrodes disposed on the substrate, and a coating formed on the at least three electrodes, the transfer member serving to form a nip region with the donating member, the transfer member, including the at least three electrodes, being stationary relative to the nip region;
- and
- voltage supply circuitry coupled to the transfer member for supplying bias voltages to the at least three electrodes so as to produce an electric field and control a position thereof at the nip region to allow the electric field to act upon and cause toner to transfer from the donating member to a toner receiving medium disposed between the donating member and the transfer member in the nip region during a toner transfer operation, the transfer member being separate from the toner receiving medium;
- wherein the at least three electrodes comprise a center electrode and at least two guard electrodes disposed at opposed sides of the center electrode, the center electrode for generating and controlling a magnitude of the electric field, and the guard electrodes for controlling the shape of the electric field at the nip region, and
- wherein a slope of the electric field on an output side of the nip region has a magnitude that is at two times greater than a magnitude of a slope of the electric field on an input side of the nip region.
Dependencies are inferred from the claim text.