Eastman-kodak Company

Xerox Corporation

Richard S Fox

Frederick J Case

Ramesh Nagarajan

Francis Kapo Tse

Barbara Lynn Farrell

Frank Hacknauer

Thomas I Yeh

Satyan R Kalyandurg

Salvatore C DeFazio

Blaise P Pelligra

George W Lahue

Andre M Blaakman

The background grey-level of a document is determined based on the gain of the document. A histogram is generated and compressed. The standard deviation of the distribution curve of the compressed histogram is determined. A gain factor is determined using the mean and standard deviation. Using the background grey-level, the dynamic range of the document is adjusted.

Method for determining document background for adjusting the dynamic range of an image of the document

An apparatus for controlling a flow of developer material in a development station. Gating means for regulating the flow of developer material in a development station are mounted for movement between an open position, allowing a flow of developer material and a closed position inhibiting the flow. An abutment, movable with the gating means, has a pair of opposed surfaces and contacts a limiting surface when the gating means is in the open position. A crank is drivingly connected to a drive means. The crank has a portion which engages one of the opposed surfaces when the drive mechanism moves the crank in one direction. This causes the gating means to move toward the open position. The crank engages the other opposed surface when the drive means moves the crank in an opposite direction. This causes the gating device to move to the closed position.

Apparatus for controlling the flow of developer material in a

A seal-forming device for a replenishment toner receiving aperture of a development apparatus includes a resilient member mounted to the development apparatus and around the aperture. The seal-forming device also includes a woven fabric that is mounted to the resilient member and to a part of the development apparatus. The woven fabric has warp and filling fibers. The warp fibers are larger than the filling fibers and are mounted to lie in the direction of loading and unloading a replenishment toner container relative to the seal-forming device.

Seal-forming device for a toner receiving aperture

A developer material mixing blender includes a shaft and self-locking segments. Each segment has a hollow hub, an inner ribbon for moving material towards one end, an outer ribbon for moving material in a second stream towards another and opposite end, and an interstream cross-mixing rib for moving material laterally from one to the other of the first and second streams in order to insure good mixing.

Dual-flow ribbon blender having interstream mixing member

In electrographic apparatus a magnetic brush development station has a housing with a sump for holding a supply of developer material, and a magnetic brush that applies developer material from the sump to a latent image on a photoconductor. A rotatable transport roller is located between the sump and the magnetic brush. A magnet in the roller attracts developer material from the sump to the roller so that rotation of the roller can move the material toward the magnetic brush. A gating and metering member in the form of a cylindrical tube is positioned around the roller and spaced from it. The tube has two elongate, spaced slots, and the tube is rotatable between first and second positions. When the tube is in one of its positions developer material from the sump can pass through one of the slots to the roller and be transported to the other slot where it is metered to the magnetic brush. When the tube is in its second position the slots are offset from the sump and the brush to block the flow of developer material to the transport roller and to the magnetic brush.

Magnetic brush development apparatus having a gating and metering

Sheet feed apparatus comprising means in engagement with the topmost sheet of the supply stack for feeding discrete sheets seriatim from the top of the stack in response to a feed signal. The level of the top sheet in the stack is sensed and a position signal is produced which corresponds to the top sheet level. The timing of the feed signal is varied in accordance with the position signal so that the topmost sheet is fed to arrive at a sheet utilization device during a predetermined portion of the time cycle of the utilization device regardless of the level of the supply stack.

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Rochester, NY, United States of America

Richard S Fox