Nova Patents
USRE35698E

Donor roll for scavengeless development in a xerographic apparatus

Claim Score by NHIP

Read claim 8, the broadest

Abstract

A donor roll for the conveyance of toner in a development system for an electrophotographic printer includes an outer surface of phenolic resin. The resin is doped to a suitable conductivity to facilitate a discharge time constant thereon of less than 300 microseconds. The donor roll is used in conjunction with an electrode structure as used in scavengeless development.

Term

Term ended

Expired 14 September 2015, 11 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

12 claims: 3 independent, 9 dependent

  1. 1.
    1. An apparatus for developing an electrostatic latent image, comprising:PA1 a housing defining a chamber for storing a supply of developer material therein;PA1 a donor roll, having an outer surface .�.including phenolic resin.!., mounted at least partially in the chamber of said housing, said donor roll being adapted to advance developer material to the latent image, with the discharge time constant of the surface of the donor roll being less than 300 microseconds;and PA1 an electrode member positioned in the space between the latent image and the donor roll, the electrode member being closely spaced from the donor roll and being electrically biased to detach toner particles from the donor roll so as to form a toner powder cloud in the space between the electrode member and the latent image with detached toner particles from the toner cloud developing the latent image.
  2. 7.
    7. An apparatus for developing an electrostatic latent image, comprising:PA1 a housing defining a chamber for storing a supply of developer material therein;PA1 a donor roll mounted at least partially in the chamber of said housing, said donor roll being adapted to advance developer material to the latent image;and PA1 an electrode member positioned in the space between the latent image and the donor roll, the electrode member being closely spaced from the donor roll and being electrically biased to detach toner particles from the donor roll so as to form a toner powder cloud in the space between the donor roll and the latent image with detached toner particles from the toner cloud developing the latent image;PA1 wherein the electrical discharge time constant of the surface of the donor roll is less than 300 microseconds.
  3. 8.
    8. An apparatus for developing an electrostatic latent image on a charge-retentive surface, comprising:PA1 a housing defining a chamber for storing a supply of developer material therein;and PA1 a donor roll mounted at least partially in the chamber of said housing, said donor roll being adapted to advance developer material to the latent image, including a conductive inner portion and a substantially non-metallic outer layer, wherein the thickness of the outer layer divided by the dielectric constant thereof is less than the distance between the donor roll and the charge-retentive surface.
Independent claims3