Xerox Corporation

Joseph L Scaletta

Delmer G Parker

Lawrence J Fraser

A magnetizable donor is magnetized to define a microfield with a characteristic spacing between pole centers of about 0.010 inches. The strong short range fields between poles pick up and hold a thin uniform and continuous layer of magnetic toner. The layer of toner is then electrostatically charged and brought into close proximity to a receptor, without touching the same, where only latent image areas of the receptor attract toner from the donor layer.

Magnetic microfield donor system

An apparatus which renders a latent image visible by depositing developer material thereon. The apparatus includes a tubular member having a styrene-butadiene layer coated on a nonmagnetic roll. Magnets are disposed interiorly of the tubular member to attract the developer material thereto. The developer material is transported into contact with the latent image to produce a powder image thereon.

Developer roll

A magnetic brush development system including a spatially programmable electrode-type applicator roll for developing latent electrostatic images carried by an imaging surface of an electrostatic processor as the imaging surface moves through a development zone which is subjected to a substantially stationary, locally generated electrostatic field having a generally uniform intensity widthwise of the imaging surface and a preselected, non-uniform intensity lengthwise of the imaging surface.

Spatially programmable electrode-type roll for electrostatographic

To realize the advantages which sometimes attach to the use of electrically conductive carrier particles, the electrodes within development systems and cleaning systems for electrostatographic processors, such as xerographic copiers and duplicators, are coated or otherwise held in intimate contact with a sufficiently thick layer of material having a resistivity which is selected to prevent carrier caused short circuit events from producing irreversible damage and to localize the effects of such events. As a general rule, a 1-25 mil thick layer of a material having a resistivity in the range of 10.sup.7 - 10.sup.9 ohm.sup.. cm is adequate for that purpose.

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Henrietta, NY, United States of America

Joseph L Scaletta