Lexmark International, Inc.

Laura Lee Kierstein

Ronald Harold Levin

Weimei Luo

Matthew David Heid

Garry Dale Hinch

Prasanna Shrestha

Kasturi Rangan Srinivasan

David Glenn Black

Scott Thomas Mosier

Gregory Walter Haggquist

Michael Thomas Moore

Jennifer Kaye Neely

Catherine Mailhe Randolph

Eric L Ziercher

Paul Dwight Kemmesat

Michael George Sloan

Karin Ann Voll

Sterritt R Fuller, Jr

A photoconductive drum includes an elongated support element with a shaped charge generation layer. The layer extends from the support element at various thicknesses along a length thereof. Thicker charge generation portions provides denser optical densities compared to thinner portions allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. A charge transport layer overcoats the charge generation layer. Optionally, an oxidation layer underlies the charge generation layer as does a protective overcoat overlying the charge transport layer. Various thicknesses and shapes of the charge generation layer are also disclosed.

Shaped charge generation layer for a photoconductive drum

Shaping a photoconductive drum includes preparing a dispersion having a charge generation composition and dipping an elongated support element into the dispersion. Withdrawing from the dispersion portions of the support element at different speeds results in different thicknesses of charge generation composition on the support element. Faster withdrawal results in thicker charge generation composition than does slower withdrawal. Portions with thicker composition provide denser optical densities compared to thinner composition allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. Coating the support element with a charge transport layer occurs next, then curing. Oxidation of the support element may occur prior to application of the charge generation composition. A protective overcoat may also exist over the charge transport layer.

Method for a shaped charge generation layer for photoconductive drum

Charge generation layers comprise a type I polymorph of titanyl phthalocyanine prepared by pre-milling a type IV polymorph in a media mill. Dual layer photoconductors comprise the charge generation layer in combination with a substrate and a charge transport layer.

Methods for making a charge generating layers comprising type I

Charge generation layers for photoconductors comprise a binder and a charge generation compound, wherein the binder comprises a blend of polyvinylbutyral polymer and at least one resin which improves at least one electrical characteristic of a photoconductor in which the charge generation layer is included. Photoconductors comprise the charge generation layer in combination with a substrate and a charge transport layer.

Photoconductor with charge generation binder blend

Methods of making a charge generation layer comprise premixing a charge generation compound, a charge transport compound and solvent to form a premix essentially free of polymeric binder, mixing the premix with at least one polymeric binder to form a dispersion, and coating the dispersion on a substrate. Photoconductors comprising a substrate, a charge transport layer and a charge generation layer formed by such a method exhibit improved electrical sensitivity.

Methods of making charge generation layers containing charge transport

An electrophotographic photoconductor containing an aromatic polycarbonate binder resin and silicone microspheres provides improved wear resistance, increased useful life of the photoconductive drum, a high quality image over the life of the photoconductor, and improved coating uniformity.

Photoconductor containing silicone microspheres

A positive charging photoconductor of, preferably, 4 to 8 percent by weight metal-free phthalocyanine, 30-50 percent by weight tritolylamine and the remainder polyvinylbutyral.

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Johnstown, CO, United States of America

Laura Lee Kierstein