Hewlett-packard Company

Hewlett-packard Development Company, L.p.

John A Thompson

Kenneth Eugene Heath

George Bernhard Clifton

C S Chan

Peter Gysling

David Punsalan

Bruce J Jackson

Wayne J Schmidt

Carl D Geleynse

John H Stewart

Kristina J Barnes

Fluid filtration systems and methods thereof to filter fluid in a first directional mode and a second directional mode are disclosed. Fluid filtration systems and methods thereof include a first directional mode, a second directional mode, and a filter unit. The filter unit includes a filter housing unit and a filter chamber disposed in the filter unit.

Method for filtering carrier oil

An ink carrier oil and water are separated from condensate. One embodiment includes first and second chambers for the separation. The first chamber receives the condensate and has an upper discharge outlet and a lower discharge outlet. The second chamber has an inlet connected to the lower outlet and a second chamber outlet below the upper discharge outlet such that separated carrier oil is discharged through the upper outlet. Separated water is discharged through the second chamber outlet. An interface between the separated carrier oil and water extends between the upper discharge outlet and the lower discharge outlet. In another embodiment, the carrier oil includes at least one of a high molecular weight oil, a lubricating oil and a defoamer. An additive having a lower concentration of the at least one of the high molecular weight oil, the lubricating oil and the defoamer is added to the carrier oil.

Condensate separation

Inorganic semiconductive films are made by depositing a suitable precursor substance upon a substrate, irradiating the precursor substance with electromagnetic radiation to form a nascent film, and heating the nascent film at a predetermined temperature to form an inorganic semiconductive film.

Methods for making and using high-mobility inorganic semiconductive films

In a color electrophotographic printing system using a transfer belt, residual toner remains on the surface of the transfer belt after the printing of a page. To prevent print defects from occurring, the residual toner on the surface of the transfer belt must be removed. A transfer belt charge roller driven by a high voltage power supply is used to positively charge the residual toner to permit electrostatic transfer of the residual toner from the surface of the transfer belt to the surface of a photoconductor drum for removal by a cleaning blade. By applying an AC waveform and a positive DC offset, the residual toner is effectively positively charged for electrostatic removal from the transfer belt.

System for charging toner on a toner carrying member for removing toner

The development of the edges of discharged areas on a photoconductor drum in an electrophotographic printing system is controlled by the ratio of the DC component of the developer bias to the magnitude of the difference between the DC component of the developer bias and the DC component of the bias supplied to the photoconductor charge roller. A development system using a developer, a photoconductor charge roller, a high voltage power supply, an optical density sensor, and a controller for controlling the high voltage power supply optimizes the electrophotographic edge development. The optical density sensor is used in a calibration process to determine the value of the DC component of the developer bias necessary to ensure the optical density of developed areas will meet the minimum specified optical density. Optimization of the edge development is accomplished by controlling the high voltage power supply so that the difference between the DC component of developer bias and the DC component of the photoconductor bias is maintained at a substantially constant value as the DC component of the developer bias is adjusted on successive calibrations.

Optimization of electrophotographic edge development

An imaging system carries an image defined by a dry powder or liquid toner. The imaging system includes a first transfer roll that electrostatically or adhesively accumulates the color image from a photoconductor, and a second transfer roll in transfixing contact with the first transfer roll. The second transfer roll possessing a central radiant heat source and a radiant heat source located adjacent to the first transfer roll in radiant proximity to an entering media sheet and the transfixing contact between the first and second transfer rolls. The first transfer roll includes at least a first basecoat layer and a topcoat layer. The basecoat layer includes a material that is electrically conductive and exhibits elastomeric and macrocompliant properties enabling the media to wrap through a significant arc under the transfixing contact and heat of the second transfer roll. The topcoat layer includes a specially formulated Fluorosilicone topcoat material that has a low surface energy and exhibits a microcompliance and resiliency enabling the first layer to compliantly mate with the photoconductor surface. The second transfer roll includes an outer, liquid carrier phobic layer and an inner compliant layer for enabling direct transfer of an image from the first transfer roll to a media sheet. The second transfer roll is optionally electrically biased with a polarity to prevent premature transfer of the image on the first transfer roll.

Dry powder or liquid toner image transfixing system

A foam roller cleaning system for removing excess toner and carrier in an LEP printer includes a foam roller, having a reduced outer foam layer thickness, that is retractably engagable with an adjacent wringer bar for selective yet complete compression of the foam roller. The outer foam layer thickness is reduced to limit the volume of toner that can accumulate in the foam and, consequently, to reduce the build-up of toner solids therein. The complete compression of the outer foam layer by the wringer bar ensures removal of substantially all toner from the foam to prevent toner solids build-up and to improve cleaning of the foam. The retractable engagement of the foam roller with the wringer bar prevents compression set in the foam roller for improved cleaning of the developer and rigidizing/squeegee rollers and improved useful life of the foam roller.

Foam roller cleaning system for a liquid electrophotographic printer

An electrostatic imaging system includes a photoconductor which carries an image defined by a liquid toner. The liquid toner comprises a pigment binder system in a paraffinic solvent blend carrier liquid, the liquid carrier exhibiting a relatively high flash point temperature. The imaging system further includes a heating roll, and a film forming roll positioned between the photoconductor and the heating roll. The film forming roll includes at least first and second superposed layers, the first layer comprised of a material that is carrier liquid phillic and which exhibits a dimensional thickness which enables substantially all carrier liquid entrained therein to reach the liquid's flashpoint temperature when under influence of the heating roll. The second layer is carrier liquid phobic and exhibits a resiliency that enables the first layer to compliantly mate with the photoconductor surface. A further transfer roll comprises an outer, liquid carrier phobic layer and an inner compliant layer for enabling indirect transfer of an image from the photoconductor to a media sheet.

Liquid toner fusing/transfer system with a film-forming roller that is

The invention is a liquid toner developer for a laser printer. There is an open bath of liquid toner about 50 microns below a moving outer bottom photoconductor surface energized by actinic light. Immediately downstream of the liquid bath and adjacent to it is a charged, reverse direction developer roller, also about 50 microns below the photoconductor surface. Downstream of the developer roller, and in relatively close spaced-apart relationship from it, is a same direction rigidizing/squeegee roller charged about the same as the developer roller. A blade lies close to or in contact with the rigidizing/squeegee roller slightly upstream of its nip point to provide a drain path along the length of the roller to aid excess toner removal from the roller. A common wiping means cleans both the developer and the rigidizing/squeegee rollers, and directs excess toner into a recycle system to save toner supply and replenish the bath of liquid toner. The image on the photoconductor surface leaving the developer system is very dry, and suitable for direct transfer to a sheet of paper. In a preferred embodiment, a series of the developer systems with different color toners are employed to create a multi-color image on the paper.

Liquid electrophotographic printer developer

A thermo-electric image transfer system (50) for transferring a toned image directly to a paper or transparency medium in the absence of a liquid toner carrier. The medium is fed over a pre-heating platen (52) which drives excess moisture out of the medium. The medium is fed into a nip between first and second transfer rollers (64, 62). The first transfer roller (64) is heated so as to heat the backside of the medium, and includes a thermally and electrically conductive elastomeric layer (64A). A guide element (66) guides the medium out of the nip between the transfer rollers, and into another nip between the first transfer roller (64) and the photoconductor drum (68), with pneumatic cylinders maintaining pressure between the roller and drum. An electrostatic bias voltage is applied to the first roller (64) of a polarity opposite to that of the toner defining the image on the drum (68), to provide an electrostatic attraction of toner to the medium. The heat, pressure and electrostatic fields causes a toner image to be transferred to the medium from the drum (68). The medium is allowed to remain against the drum (68) to allow for cooling and adhesion to the medium, and thereafter is detached from the drum, with the image separating at the toner/photoconductor interface.

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Boise, ID, United States of America

John A Thompson