Eastman-kodak Company

Nexpress Solutions, Inc.

Kenneth Joseph Brown

Charles Herbert Hasenauer

Joseph A Kwiatkowski

Donald Saul Rimai

Michael Thomas Dobbertin

Francisco Luiz Ziegelmuller

Dennis J Grabb

George David Gross

David S Kepner

Thomas Nathaniel Tombs

Eric C Stelter

Diane Marie Herrick

David E Hockey

Christopher Stephen Garcia

Paul Essic Thompson

Theodore H Morse

David McLaughlin Rakov

Carol K Dunn

Donald Steven Hensel

David L Thompson

Laverne N Lincoln, Jr

Maria B Carrone

Gary Edwin Nichols

Allan R Amering

Douglas C Anderson

Charles D Odum

James George Blum

Amy J Deyaeger

A toner replenishment apparatus for a dry electrophotographic (EP) printer includes a rotatable transport subsystem in the developer. The subsystem includes an elongated housing with a feed port and various apertures arranged along its length. A channel within the housing receives toner from the toner supply through the feed port. A toner transport member in the channel moves toner received through the feed port to the apertures, and a developer-mixing member attached to the outside of the housing mixes toner and carrier particles in the developer. The toner transport member is stationary or rotates at a different angular velocity than the housing. When the rotation of the transport subsystem brings a selected one of the apertures below the center of the housing, toner passes through the selected aperture into the developer in the sump, and is mixed into the developer by the developer-mixing member as the transport subsystem rotates.

Electrophotographic developer toner replenishment apparatus

Developer density in an electrophotographic system is measured. The developer includes toner particles and magnetic carrier particles. First and second mutually-insulated electrodes define a working volume between them through which developer passes without contacting the first electrode. An AC voltage or current source is connected to the electrodes. An inductor is connected in series with a voltage source, or an inductor is provided in parallel with a current source. The voltage or current is applied and corresponding current or voltage across the electrodes is measured. The density of the developer in the working volume is automatically determined using a processor responsive to the measured current or voltage and the applied bias.

Resonant-frequency measurement of electrophotographic developer density

A method of making a slotted scavenger wherein a rigid sheet is used as a starting material. A slot is formed through the sheet having horizontally angled sidewalls such that an opening of the slot on a first major surface of the sheet is smaller than an opening of the slot in a second major surface of the sheet. Modifications of the method include using a rotating cutting tool for cutting through the sheet to form slots.

Fabrication on of an alternate scavenger geometry

A method for removing carrier buildup in a slotted scavenger electrode in a printer comprising magnetically attracting the carrier toward the slot, blocking the slot with a movable flap for preventing toner dust from traveling through the slot, opening the movable flap for allowing the carrier to travel through the slot and return to the developer station, then reclosing the movable flap.

Method of implementing a magnetically actuated flap seal

Developer density is measured in an electrophotographic system. First and second electrodes are disposed to define a working volume between them through which developer passes without contacting the first electrode, wherein the electrodes are electrically insulated from each other by the working volume. One terminal of an AC voltage (current) source having a selected frequency is connected to one of the electrodes. An inductor is connected in series (parallel) with the voltage source, so that the source provides the AC bias (current) across the electrodes through (across) the inductor. The AC is applied and the current (voltage) across the electrodes is measured. The density of the developer in the working volume is automatically determined using a processor responsive to the measured current (voltage) and the applied bias (current).

A piezoelectric crystal adjacent to a development member in an electrophotographic printer has an electrode on it facing the development member. An AC bias is applied across the crystal while a DC bias is applied between the electrode and the development member to measure toner-mass deposition rate. An AC bias is then applied between the electrode and the development member to measure developer flow rate. The toner concentration of the developer is determined using the measured toner mass-deposition rate and developer flow rate.

Determining developer toner concentration in electrophotographic printer

Developer toner concentration in an electrophotographic system is measured. Two sensors, one before and one after the toning zone in the direction of rotation of the development member, each include respective electrodes that form a respective capacitance between the respective electrode and the development member. A voltage source selectively applies respective AC biases across the sensors and the respective currents across the sensors are measured. A controller causes an electrostatic latent image to be produced on the photoreceptor and causes the development member to rotate and the photoreceptor to move. While the development member is rotating, the processor receives the measured currents and computes toner concentration using the respective received currents and the pixel data. The developer flow rate can be adjusted, or toner added to the developer, in response to the determined toner concentration.

Electrophotographic developer toner concentration measurement

A printer having a developer station for holding a supply of developer which includes magnetized carrier particles, a magnetized development roller, and an imaging roller proximate the development roller which collects carrier particles during operation of the printer. A scavenger proximate the imaging roller and the development roller removes the carrier particles from the imaging roller during operation of the printer which are then urged through a slot in the scavenger by the magnetized development roller.

Printer having an alternate scavenger geometry

Background development in a multi-color electrophotographic printer is reduced. A print job including a plurality of separations is received. Each separation has an image area and a non-image area. A printer is provided, including a development member for supplying toner to a photoreceptor for each separation. A developing and a non-developing zone are determined for each separation, corresponding to the image area and non-image area, respectively. Developer is automatically supplied to the development members, and automatically removed developer from the respective non-developing zone of each development member.

Reducing background development in electrophotographic printer

A printer includes a development member for providing toner to a photoreceptor. A developer remover is located between a developer supply and the photoreceptor in the direction of rotation of the development member, and selectively contacts the development member to remove developer therefrom. A controller receives a print job, determines a non-developing zone of the development member corresponding to the non-image area of the job, and determines a developing zone of the development member corresponding to the image area of the job. The developer remover removes developer when it is in the non-developing zone, but not when it is in the developing zone.

Printing job with developer removal

A metering skive for a developer roller which is adapted to shear and/or meter developer at a developer-skive interface while minimizing compression of the metered developer. The metering skive is adjustable to various shear angles and has a geometry which enables a portion of the developer flow to be sheared away toward a curved second surface of the metering skive while metering the developer flow in a manner which minimizes or reduces compression of the developer.

Metering skive for a developer roller

An apparatus and method for managing magnetic carrier in an electrostatographic printer including an apparatus for directing magnetic carrier from a photoconductor, back toward a feed apparatus wherein the apparatus includes a magnetic carrier scavenger such that there is more magnetic carrier volume in the direction of the feed apparatus as well as a well to collect any magnetic carrier that does not move toward the feed apparatus.

Magnetic scavenger for an electrostatographic printer

Flat field uniformity can be improved in images produced by an image development system having a development roller interposed between a supply of developer and an imaging element. A raw feed of developer is supplied from the developer supply to the development roller to produce both a metered feed of developer and an overfeed of developer, which is returned to the supply, from the raw feed. A plurality of mass densities of developer used in the system and a plurality of developer velocities through the system are determined, and respective product values of those developer mass densities and those developer velocities are thereafter calculated or otherwise determined. A maximum value of the respective product values is identified, and the image development system is then operated so that the maximum product value is produced.

Method of improving developed flat field uniformity

An apparatus and method for dispensing toner in an electrostatographic printer includes an apparatus for feeding powder toward the feed apparatus wherein the feed roller includes a tapered feed roller including a shaft and one or more variable height flutes such that there is more developer volume in the direction of flow as well as a conveyance controller for controlling the powder conveying device, including the one or more tapered feed rollers such that the tapered feed roller preferentially uniformly conveys the powder toward the feed apparatus.

Powder transport with a tapered feed roller of an electrostatographic printer

An apparatus and method for dispensing toner in an electrostatographic printer includes an apparatus for transporting powder into a developer station containing at least powder and magnetic carrier including a conveyance housing divided into a mixing space adjacent to a second separate transport space, the second transport space located adjacent to a development roller, a powder conveying device located in the conveyance housing comprising two or more augers and a conveyance controller for controlling the powder conveying device, including the one or more augers, such that the auger preferentially mixes in the first mixing space and transports in the second transport space as the powder conveying device conveys the powder toward the imaging device of a print engine.

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Penfield, NY, United States of America

Kenneth Joseph Brown