Eastman-kodak Company

Richard A Weitzel

Thomas K Hilbert

James C Maher

Susan P Westbrook

Edward T Miskinis

Arthur S Kroll

Kelly Stephen Robinson

Theodore H Morse

Bruce J Rubin

Carl R Bothner

Timothy Gilbert Armstrong

Vladimir S Guslits

Clyde M Creveling

Douglas C Anderson

Larry W Speer

Peter M Stacy

Gregory L Miller

A sensor measures the toner applying capability of a toning station. It includes a transparent conductive rotatable member which is rotated through a developer applying zone and a sensing position remote from the developer applying zone. Toner is applied by developer in the station to the exterior surface of the rotatable member as controlled by a bias applied to the rotatable member. The applied toner is sensed by a transmission densitometer at the sensing position. The output can be used to control toner concentration, an original charge on an image member or a development bias applied to the toner station.

Sensor for measuring toner applying capability

A toner monitor which measures the magnetic permeability of the developer mix uses a coil around the toner monitor so that when energized with a DC current, the coil acts as an electromagnet to align the developer mix in a consistent fashion at the monitor. The permeability of the mix is measured and the DC current to the coil is inhibited allows the measured sample to fall away or be moved away from the sensor by mixing augers or paddles. When current to the coil is once again restored, another sample is captured and aligned with the monitor. Information concerning the permeability of the developer mix is used to control replenishment of the toner.

Toner monitor having magnetic field control

A toning station particularly usable in a multicolor image-forming apparatus includes an applicator and a developer mixing mechanism. A transport roller with a fluted surface transports developer from the mixing device to the applicator. A magnetic gate is positioned inside the transport roller and has a first position in which it attracts developer from the mixing device to the transport roller to facilitate delivery of developer to the applicator. The magnetic gate is movable to a position opposite the applicator where it inhibits passage of developer to the applicator to stop the development action of the station.

Toning station for selectively applying toner to an electrostatic image

Image forming apparatus includes a toner cleaning device for cleaning toner off an image surface. The cleaning device includes a cleaning applicator for moving magnetic particulate cleaning material past the surface to be cleaned. Particulate material is moved from a sump to the cleaning applicator by a transport positioned between them. A detoning roller is positioned to attract toner from particulate material associated with the transport. When the cleaning device is not cleaning, it has a mode of operation in which the transport and the detoning roller continue to operate to continue to detone particulate material which moves from the sump around the transport and back to the sump.

Image forming apparatus having toner cleaning device

A magnetic brush development apparatus for applying developer material to a latent electrostatic image wherein the mixing of pigmented marking particles in the developer material is enhanced. The development apparatus includes a housing having a portion defining a sump adapted to contain a supply of developer material to which marking particles may be selectively added. A magnetic brush is located substantially within the housing in spaced relation to the sump portion for applying developer material to the latent image. A feed mechanism, located within the housing between the sump portion and the magnetic brush transports developer material from the sump to the magnetic brush. An agitating and transporting mechanism, located in said sump portion, agitates developer material and transports developer material to the feed mechanism. In order to enhance the mixing of developer material, flow of developer material is directed from the wall of the housing adjacent to the sump portion back into the agitating and transport mechanism.

Device for improving mixing in a magnetic brush development apparatus

Scavenging apparatus for removing substantially all unwanted particles from the image and non-image areas of an electrostatographic imaging member without appreciable adverse effects on the desired image remaining thereon, includes an alternating pole magnetic roller for rotatably creating a fast changing magnetic field, a stationary ac biased shell for enclosing the magnetic roller and for creating a low, but fast changing electrostatic field, and a low vacuum system. This apparatus combines the effects of such magnetic and electrostatic fields with those of the low vacuum system to gently loosen and effectively remove unwanted particles from the imaging member, without resort to relatively strong electrostatic field and vacuum values that are likely to adversely affect the desired loose toner image still on the imaging member.

Scavenging apparatus

In a magnetic brush developer station for an electrostatographic reproduction apparatus, the developer station including a housing adapted to contain developer material, a mixer for such developer material, a magnetic brush for applying developer material to a charge pattern bearing member, and a mechanism for transporting developer material from the mixer to the magnetic brush. The transporting mechanism comprises a roller having members, located about the periphery of thereof, for picking up a quantity of developer material. The roller is mounted within a portion of the interior wall of the housing so as to be rotatable about its longitudinal axis. The wall portion of the housing is a segment of a cylinder whose axis is offset in relation to the longitudinal axis of the roller, so that, in the direction of rotation of the roller, the respective pickup members are closest to the wall at the entrance thereto and farthest from the wall at the exit thereto.

Developer station for a reproduction apparatus

Skiving apparatus for use in electrographic copiers for stripping magnetically attractive developer from the outer sleeve of a magnetic brush applicator. Such apparatus comprises an elongated and flexible skive blade and means for applying equal and opposite axial forces at spaced locations along the blade to produce tension in the skive blade and thereby provide a straight skiving edge. Preferably, the skive blade is made of a magnetically attractive material so that it is attracted toward the magnetic core piece of the brush applicator.

Tensionable skive for magnetic brush application

An electrographic development apparatus comprises a magnetic brush applicator having cooling means for dissipating thermal energy from the developer as it is transported by the brush. Such cooling means preferably comprises means for passing a cooling fluid through the interior of the brush while in use. Alternatively, such cooling means comprises a hollow skive through which a cooling fluid is circulated.

Electrographic development apparatus

A development roller comprising an electrically-conductive core and an electrically-insulative surface layer is biased to retain a monolayer of conductive toner on the surface, and moved into transfer relation with an electrostatic image bearing member to develop the image. The potential level of the toner can be controlled in conjunction with the roller bias to eliminate background or effect image reversal development.

Electrographic development apparatus for use with conductive toner

A flexible latent image-bearing photoconductive element is driven through a U-shaped path to form a self-contained electrographic developer reservoir to which electrically conductive toner particles are supplied. A grounded, electrically conductive, apertured member positioned in the toner reservoir in close proximity to the image-bearing surface of the photoconductor imparts continuous motion to the toner particles as the image-bearing element moves therepast. The motion creates a sweeping action which reduces the amount of toner background present in a finished print.

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Hilton, NY, United States of America

Richard A Weitzel