Xerox Corporation

David Antwone Reed

Ajay Kumar

Keith Allan Nau

Jonathan David Sadik

Hirotsugu Oba

Cory Joseph Winters

Richard L Kjar

John F Knapp

Michael D Thompson

Rachael L McGrath

Paul Windsor Morehouse, Jr

Rasin Moser

Jennifer R Wagner

Song Feng Mo

Allen T Retzlaff

A magnetic roll having longitudinal grooves machined in its rotating sleeve enables a pair of rolls to be rotated in a direction opposite to the direction of a photoreceptor moving through a development zone and a trim blade to be mounted proximate one of the rolls at a trim gap of approximately 0.5 to 0.7 mm. The magnetic roll includes a stationary core with at least one magnet, and a sleeve having longitudinal grooves that is mounted about the stationary core so that the sleeve rotates about the stationary core. The sleeve has a relatively smooth surface area between the grooves.

Xerographic developer unit having multiple magnetic brush rolls with a grooved surface

A development station that improves toner halftone dot development over a wide range of environmental conditions includes a developer housing for retaining semi-conductive carrier particles and toner particles, a first magnetic roll having a stationary core with at least one magnet and a sleeve having longitudinal grooves that rotates about the stationary core of the first magnetic roll, a second magnetic roll having a stationary core with at least one magnet and a sleeve having longitudinal grooves that rotates about the stationary core of the second magnetic roll, an environmental sensor for generating an environmental condition signal, a variable voltage supply coupled to the first magnetic roll and the second magnetic roll, and a control circuit for adjusting an output level for the variable voltage supply.

Environmental controls for operation of an electrostatographic developer unit having multiple magnetic brush rolls

A development station in an electrostatographic imaging machine supports longer operational life without undue variation in the mass of developer on roll parameter. The development station includes a developer housing, for retaining a quantity of developer having semi-conductive carrier particles and toner particles, a first magnetic roll having a stationary core with at least one magnet and a sleeve having longitudinal grooves that rotates about the stationary core of the first magnetic roll to transport developer to a photoreceptor, a second magnetic roll having a stationary core with at least one magnet and a sleeve having longitudinal grooves that rotates about the stationary core of the second magnetic roll to receive developer from the first magnetic roll and present the developer to the photoreceptor, the sleeve of the second magnetic roll being fabricated from a material that is softer than the sleeve of the first magnetic roll.

Electrostatographic developer unit having multiple magnetic brush rolls having dissimilar compositions

A development station in an electrostatographic imaging machine impedes the flow of carrier particles out of the development station as the developer moves from an upper to a lower magnetic roll. The development station includes a developer housing, for retaining a quantity of developer having semi-conductive carrier particles and toner particles, a first magnetic roll having a stationary core with at least one magnet and a sleeve having longitudinal grooves that rotates about the stationary core of the first magnetic roll to present developer on one side of the first magnetic roll to the photoreceptor, a second magnetic roll having a stationary core with at least one magnet and a sleeve having longitudinal grooves that rotates about the stationary core of the second magnetic roll to receive developer from the first magnetic roll and present developer on one side of the second magnetic roll to the photoreceptor, the second magnetic roll being vertically displaced from the first magnetic roll so that a gap exists between the first and the second magnetic rolls, and a magnetic seal located in the gap between the first and the second magnetic rolls to impede the outflow of carrier particles from the developer moving from the first magnetic roll to the second magnetic roll.

Electrostatographic developer unit having multiple magnetic brush rolls with a magnetic restrictor for carrier particle emission control

In a basic design of a developer unit for electrostatographic printing apparatus, an exit port is defined in the housing of the developer unit, for the passage of waste or surplus toner therethrough. An insert, defining a predetermined spillover barrier height and a predetermined exit angle, is associated with the exit port. Different types of inserts can be provided for operating the basic design of developer unit at different print output speeds, or with different compositions of developer material.

Xerographic developer unit with specialized exit port for developer material

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Rochester, NY, United States of America

David Antwone Reed