Lexmark International, Inc.

Funai Electric Company Ltd.

Pramod K Sharma

Ashok Murthy

Gregory Lawrence Ream

Peter E Wallin

Alexander D Meade

Todd Lucas Janes

Kuangti T Cheng

Bradley Leonard Beach

Jichang Cao

Ajay Kanubhai Suthar

James Douglas Gilmore

Alan Stirling Campbell

Michael John Dixon

Terence E Franey

Peter Brown Pickett

John Edward Borsuk

David Daniel Dreyfuss

Robert Galon Newman

Mark Kevin DeMoor

Jeanne Marie Saldanha-Singh

Ryan David Brockman

Carla M Butler

Matthew C Comstock

Joe D Moss

Bruce A DeBoard

Michael A Marra Iii

In an imaging device having a photoconductive drum and a lubricant applicator brush, methods and apparatus teach application of the lubricant to the drum at a transfer nip and removing undeveloped toner particles. A first voltage is applied to the drum while the brush receives a voltage that switches more positive and more negative than the first voltage. It attracts to the brush from the drum negatively and positively charged toner. Embodiments contemplate amounts of voltages and frequencies of switching. An elongate rod contacts the brush downstream of the transfer nip to flicker off the toner particles from the brush. The rod can also have voltages applied and switched greater than and lesser than the voltages of the applicator brush to facilitate toner removal. A cleaning blade downstream of the transfer nip scrapes clean a surface of the drum.

Biased lubricant applicator brush in imaging device

The present application is directed to methods of controlling the transfer voltage in a transfer nip formed between the photoconductive member and the transfer member. The methods offset the effects of large transfer current spikes caused when a media sheet enters and exits the transfer nip. The control may include either ramping up or ramping down the transfer voltage. The ramped transfer voltage may include a series of alternating positive and negative steps that generally trend to ramp up or down. The size of the steps may further be adjusted to provide a smooth transition.

Methods for transfering toner in direct transfer image forming

An image transfer assembly in a color printer or the like includes four image forming units. Each of the image forming units includes a photoconductive unit and a transfer device. A voltage is applied to the transfer device thereby creating a voltage potential between the photoconductive unit and the transfer device to facilitate the transfer of toner to a media substrate, such as paper. The transfer devices in the first two image forming units share a single high voltage power supply while separate high voltage power supplies supply the necessary voltage to the transfer devices of the other two image forming units.

Shared high voltage power supply for image transfer in an image forming device

A fuser assembly within an image forming apparatus having a paper path along which substrates travel through the image forming apparatus including a heating member and a backup member cooperating with the heating member to form a nip therebetween for fusing images onto substrates passing through the nip. Also provided is structure for conveying substrates along the paper path to the nip, and a processor. The processor determines a relative humidity, determines if the relative humidity is above a predefined value corresponding to undesirable substrate curl; sets an interpage gap between conveyed substrates to a nominal value if the relative humidity is below the predefined value; and determines if the interpage gap should be increased beyond the nominal value if the relative humidity is above the predefined value. A corresponding method is provided.

Method and apparatus for reducing sheet material curl induced in a fusing operation

An image forming device prints on specialty media comprising a first and second area having different media properties. The device prints on the first area at a first transfer voltage level selected in response to a media property of the first area. The device prints on the second area at a second transfer voltage level selected in response to a media property of the second area. The device changes from the first transfer voltage level to the second transfer voltage level when a predetermined location on the specialty media, on which no image is formed, is within the transfer nip.

System and method of image formation on specialty media by altering interpage transfer voltage or current

Method and apparatus are provided for inhibiting toner transfer defects, and in particular, to inhibit over-transfer of electrical charge through a transfer medium to a toner after development of a latent image on a photoconductor in an electrophotographic imaging device. Toner transfer defects are inhibited near the leading edge of a print medium by a method which includes the step of providing a controlled ramped voltage output to a transfer member so as to provide a controlled flow of charge from the transfer member to the transfer medium during an initial application of electrical charge to a first region of the transfer medium adjacent a leading edge of the transfer medium. To inhibit intra-page toner transfer defects, the method of the invention includes the step of selectively activating a light source when the transfer medium is present in the nip region so as to partially discharge a portion of the photoconductor not containing a developed image when a servo voltage is below a servo threshold voltage during an image transfer.

Electrophotographic apparatus and method for inhibiting charge

In imaging apparatus (1) a contact heater (9) applies heat and electrical bias to a toner image on an intermediate accumulator (5). The bias is of polarity to repel the toner. The toner image is coalesced such that additional heating may be reduced or eliminated at the transfer to paper (7) by pressure roller (11).

Color imaging with contact transfer heating station

Cleaning roller (7) contacts intermediate transfer roller (4), each rotating at the same surface speed to avoid rubbing. The cleaning roller has an electric potential sufficient to remove toner from the transfer roller to clean it. Silicone oil is applied by a roller 29, which is wetted by oil from a oil impregnated wiper (31). The oil facilitates cleaning and reduces wear of the intermediate transfer roller, which is typically soft to facilitate transfer.

Toned member cleaning by electrified roller

A printer or other imaging apparatus (1) in which two or more images in registration are transferred from a photoconductor (3) to an intermediate transfer drum (5). The transfer drum has very stable resistivity, which is achieved by the body of the drum being cesium iodide filled polyurethane.

High stability color imaging by transfer roller

In an electrostatic printer (1) paper (11) is first conditioned by being thoroughly dried by rollers (13 and 15), which also immobilize the paper so that it does not wrinkle. The paper is then kept hot on flat plate 17 before it moves into the transfer nip of intermediate transfer drum (5) and transfer roller (7). The paper does not wrinkle on the plate and toner image is transferred to a wide range of papers with exceptional quality and consistency.

Imaging apparatus with paper preconditioning for transfer

A liquid toner having a mineral oil vehicle, a blend of Surlyn ionomeric resin and Nucrel resin, pigment and, as charge director, lecithin, N-methyl-2-pyrrolidone and calcium Petronate. The charge director optimizes speed of recovery of charge properties during continual use. The mineral oil does not vaporize well and is readily condensed, thus permitting use as a confined toner.

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Lexington, KY, United States of America

Pramod K Sharma