Lexmark International, Inc.

Matthew David Heid

Christopher David Strack

Andrew Pryse Dale

Weimei Luo

Joshua Carl Poterjoy

Laura Lee Kierstein

Christopher Michael Bennett

Prasanna Shrestha

Michael Craig Leemhuis

James Anthany Carter, Ii

Kevin Dean Schoedinger

Benjamin Keith Newman

Gregory Alan Cavill

Donald Wayne Stafford

Douglas Anthony Able

Christopher Gene Vowels

Gina Marie Johns

David John Mickan

Stephen Andrew Brown

James Craig Minor

Matthew Russell Smither

James Christopher Piotrowski

Jared Kuohui Lin

Scott Moreland Broce

Robert Joseph Firmature

Yueping Fu

Lance Tisdale Hoshiko

Karen Eileen Zrebiec

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

An imaging device includes a photoconductive drum charged by a charge roll and opposed by developer roll. The developer roll adds toner to the drum to develop a latent image on the drum for transfer to media or an intermediate transfer member at a transfer roll. One or more high voltage power supplies communicate with a controller to set voltages on the rolls. During times of non-imaging, but rotation of the drum, the charge roll charges the drum to less than a Paschen breakdown voltage of the drum. A voltage of the transfer roll is determined that corresponds to a temperature and relative humidity of an operating environment of the imaging device and the developer roll is charged based thereon. The charge of the transfer roll is set close to the charge of the drum, but higher in magnitude. A laser may also discharge the drum.

Reducing waste toner with electrophotographic voltage control in imaging devices

An imaging device includes a photoconductive drum charged by a charge roll and opposed by developer roll. The developer roll adds toner to the drum to develop a latent image on the drum for transfer to media. One or more high voltage power supplies communicate with a controller to set voltages on the rolls. The controller determines whether imaging of the media is to occur at a time when the drum is rotating. If not, a laser beam discharges the drum and the voltage on the charge roll is decreased to reduce the charge on the drum, but the controller maintains the voltage differential between the drum and the developer roll.

An imaging device prints in color and monochromatically, such as black-only. It has a plurality of photoconductive drums, one each for black toner and at least one colored toner. The drums contact and rotate with an intermediate transfer member (ITM) to transfer images at a first transfer. During black-only imaging, the photoconductive drum for the black toner rotates with the ITM at process speed while the drum for the at least one colored toner rotates at less than process speed, often substantially less. The technique reduces consumption of colored toner during black-only imaging and minimizes charge build-up on the drum for the colored toner.

Monochromatic imaging with reduced colored toner consumption and ESD defects

An imaging device has first image transfer from photoconductive drums to an intermediate transfer member (ITM) and second image transfer from the ITM to media. Transfer rolls oppose the drums from an opposite side of the ITM and electrically ground to a frame of the imaging device by mechanical connection. The rolls may be laterally offset from the drums. The ITM has relatively low surface and volume resistivity. An imaging subassembly may include the frame, the ITM, and the transfer rolls grounded to the frame.

Imaging transfer to intermediate transfer member

A removable unit for an electrophotographic imaging device includes a housing having an opening, a rotatable roll disposed near the opening and adjacent to a bottom of the housing and a blade assembly coupled to the housing. The blade assembly includes a support bracket secured to a wall defining at least a part of the opening of the housing, and a blade member coupled to the support bracket and being positioned in the removable unit so that a distal end portion of the blade member engages with the rotatable roll. The housing, the blade assembly, and a portion of a surface of the rotatable roll define a substantially sealed enclosure for containing toner therein.

Developer unit architecture for an imaging device

Generally, an imaging device is capable of applying respective EP engine settings to different zones within a page of media. In an example embodiment, a method includes printing in first and second zones on a page of media using first and second EP engine settings that are respectively associated with the first and second zones. The imaging device prints in the first zone on the page of media based on a first EP engine setting that is associated with the first zone. The imaging device switches from the first zone on the page of media to the second zone on the page of media responsive to a size indicator. The imaging device prints in the second zone on the page of media based on a second EP engine setting that is associated with the second zone.

Methods and apparatuses for applying respective EP engine settings to different zones within a page of media

An image forming equipment, e.g., a laser printer includes a photoconductive (PC) drum and an associated charge roller and incorporates a conductive polymer cleaner blade having an electrical potential to sufficiently charge contamination particles on the PC drum to electrically repel from a charged surface, such as the charge roller.

Apparatus and method of reducing charge roller contamination

The present invention relates to controlling the mass flow of toner in an image forming device or a toner cartridge. The toner composition includes extra particulate additives including a conductive additive. The extra particulate additives may also include relatively small silica particles or relatively large silica.

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Louisville, KY, United States of America

Matthew David Heid