Abstract: A device for metering developer material to a predefined developer material bed height on a donor member, including a trim bar being mounted a predefined spacing from the donor member; and a magnetic member positioned adjacent and along the length of the trim bar, the magnetic member coacting with the trim bar to obtain the predefined developer material bed height on the donor member.

Abstract: A xerographic marking device includes an intermediate transfer unit, a media transport path and at least one two-color image-on-image (IOI) drum module. Each two-color IOI drum module includes in a process order around a photoreceptor: a) a first charging unit; b) a first exposure unit; c) a first development unit; d) a second charging unit; e) a second exposure unit; and f) a second development unit, wherein the intermediate transfer unit receives a first toned image and a second toned image from the photoreceptor in a single transfer and transfers those toner images to print media to produce a toned image on print media. In various embodiments, specific color pairings are provided.

Abstract: A method (400) and apparatus (100) that detects carrier particles (130) in an electrophotographic device is disclosed. The apparatus may include an image carrying member (110). The image carrying member may have a first side (111) and have a second side (112) opposite from the first side. The image carrying member may be configured to operate in a direction of motion (115). The image carrying member may also be configured to transport an image on the first side. The apparatus may also include a magnet (120) coupled to the second side of the image carrying member. The magnet may have a length (122). The length of the magnet may be at an angle (124) of greater than zero and less than 90 degrees to the direction of motion of the image carrying member. The magnet may be configured to attract toner carrier particles transported on the image carrying member. The apparatus may also include a first sensor (140) coupled in proximity to the first side of the image carrying member and coupled in proximity to the magnet.

Abstract: A xerographic marking device includes an intermediate transfer unit, a media transport path and at least one two-color image-on-image (IOI) drum module. Each two-color IOI drum module includes in a process order around a photoreceptor; a) a first charging unit; b) a first exposure unit; c) a first development unit; d) a second charging unit; e) a second exposure unit; and f) a second development unit, wherein the intermediate transfer unit receives a first toned image and a second toned image from the photoreceptor in a single transfer and transfers those toner images to print media to produce a toned image on print media. In various embodiments, specific color pairings are provided.

Abstract: This is an electrophotographic marking system that effectively cleans residual toner and toner additives from the surface of a photoreceptor of a marking system, by improved toner and toner agent removal expedients . This cleaning process reduces ghosting problems that had been encountered in final copies produced by electrophotographic systems such as in copier, printers and duplicators. This cleaning is accomplished by expedients such as increasing a cleaning brush bias, and by increasing the surface area of cleaning brushes used in the system. In addition, the development process is desensitized to the development of ghosting. This desensitizing is accomplished by expedients such as increasing the gap between the development roll and the photoreceptor and by reducing the AC development electrical bias.

Abstract: A device for metering developer material to a predefined developer material bed height on a donor member, including a trim bar being mounted a predefined spacing from the donor member; and a magnetic member positioned adjacent and along the length of the trim bar, the magnetic member coacting with the trim bar to obtain the predefined developer material bed height on the donor member.

Abstract: A method (400) and apparatus (100) that detects carrier particles (130) in an electrophotographic device is disclosed. The apparatus may include an image carrying member (110). The image carrying member may have a first side (111) and have a second side (112) opposite from the first side. The image carrying member may be configured to operate in a direction of motion (115). The image carrying member may also be configured to transport an image on the first side. The apparatus may also include a magnet (120) coupled to the second side of the image carrying member. The magnet may have a length (122). The length of the magnet may be at an angle (124) of greater than zero and less than 90 degrees to the direction of motion of the image carrying member. The magnet may be configured to attract toner carrier particles transported on the image carrying member. The apparatus may also include a first sensor (140) coupled in proximity to the first side of the image carrying member and coupled in proximity to the magnet.

Abstract: To generate a toner cloud in a development system, a first potential is applied to a donor roll for a first pulse time to project toner from the donor roll toward a photoreceptor; a second potential is applied to the donor roll for a second pulse time to slow the speed at which the toner is projected toward the photoreceptor; a third potential is applied to the donor roll for a third pulse time to hold toner between the donor roll and the photoreceptor; and a fourth potential is applied to the donor roll for a fourth pulse time to urge undeveloped toner to the surface of the donor roll. Voltages may also be applied for selectivity removing toner from a donor roll.

Abstract: 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.

Abstract: A specific magnet roll design for high speed semi-conductive magnetic brush (SCMB) development systems for magnetic image character recognition (MICR) printing is provided. The resulting magnetic field distributions include a more uniform radial field and enhance solid area development and halftone graininess without or substantially without bead carryout issues. In addition, this enhancement of solid area development enables magnetic toner in these hill speed SCMB systems that normally would not provide sufficient development latitude for MICR.

Abstract: To generate a toner cloud in a development system, a first potential is applied to a donor roll for a first pulse time to project toner from the donor roll toward a photoreceptor, a second potential is applied to the donor roll for a second pulse time to slow the speed at which the toner is projected toward the photoreceptor; a third potential is applied to the donor roll for a third pulse time to hold toner between the donor roll and the photoreceptor; and a fourth potential is applied to the donor roll for a fourth pulse time to urge undeveloped toner to the surface of the donor roll. Voltages may also be applied for selectivity removing toner from a donor roll.

Abstract: A development subsystem is used to develop developer having semiconductive carrier particles and toner particles. The development subsystem includes a developer housing, for retaining a quantity of developer having semiconductive carrier particles and toner particles, a first magnetic roll having a stationary core with at least one magnet and a sleeve 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 that rotates about the stationary core of the second magnetic roll, and a motor coupled to the first and the second magnetic rolls to drive the rotating sleeves of the first and the second magnetic rolls in a direction that is against the direction of a photoreceptor that rotates in proximity to the first and the second magnetic rolls. The first and the second magnetic rolls carry semiconductive carrier particles and toner particles through a development zone formed by the first and the second magnetic rolls.

Abstract: A development station in an electrostatographic imaging machine may be controlled to improve toner halftone dot development over a wide range of environmental conditions.

Abstract: A developer includes black toner particles and carrier particles, the black toner particles including at least one binder, at least one black colorant and one or more external additives, wherein the toner particles comprise from about 7 to about 15 pph of the developer, and wherein the toner particles exhibit a triboelectric charge of from about ?25 to about ?50 ?C/g at toner particle concentrations of about 7 to about 15 pph of the developer. The developer is ideally suited for use in a high speed (greater than 100 prints per minute) semiconductive magnetic brush development apparatus. Preferably, the black toner particles include a styrene acrylate binder, and the external additives include from about 1.3 to about 2.1% by weight of the toner particles of a first silica having an average particle size of from about 35 to about 45 nm, from about 0.5 to about 1.0% by weight of the toner particles of a second silica having an average particle size of from about 135 to about 160 nm, and from about 0.

Abstract: An apparatus for removing charged particles from a surface, the surface being capable of movement, including: a conductive brush in contact with the surface, the conductive brush having a first region thereof having a first polarity and a second region having a second polarity; the conductive brush includes a core and conductive fibers attached thereto, the core being electrically segmented into the first region and the second region.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of a member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a variable voltage waveform onto which a DC bias is superimposed. The amount of DC bias is selected to set the signal voltage such that a minimally acceptable amount of AC corona is created sufficient for uniform photoreceptor charging while avoiding unnecessary excessive positive corona that causes excessive photoreceptor wear.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a rectified AC waveform onto which a DC bias is superimposed after the waveform has been rectified. The result is the ability to raise the voltage potential of the photoreceptor with less pulse voltage and, more particularly, to increase the voltage potential of the photoreceptor along as if only DC voltage were applied far above what is possible in the prior art. Among the advantages of the invention is the ability to minimize photoreceptor wear at higher levels of photoreceptor charge since the DC-offset bias enables the second Paschen threshold to be avoided for higher levels of the photoreceptor charge.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a rectified AC waveform onto which a DC bias is superimposed after the waveform has been rectified. The result is the ability to raise the voltage potential of the photoreceptor with less pulse voltage and, more particularly, to increase the voltage potential of the photoreceptor along as if only DC voltage were applied far above what is possible in the prior art. Among the advantages of the invention is the ability to minimize photoreceptor wear at higher levels of photoreceptor charge since the DC-offset bias enables the second Paschen threshold to be avoided for higher levels of the photoreceptor charge.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of a member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a variable voltage waveform onto which a DC bias is superimposed. The amount of DC bias is selected to set the signal voltage such that a minimally acceptable amount of AC corona is created sufficient for uniform photoreceptor charging while avoiding unnecessary excessive positive corona that causes excessive photoreceptor wear.

Abstract: A system and method of applying a controlled amount of fluid to a moveable image carrying member of an electrographic printing system using a liquid toner before an image is transferred to a substrate. The amount of fluid applied may be controlled by a re-wet roller, located between the toner station and the transfer station, whose distance from the moveable image carrying member is varied along with the rotational speed and direction of the re-wet roller, according to either the roughness and porosity of the substrate or the print quality of the substrate. Alternatively, the fluid may be directly applied just to image areas of the moveable image carrying member to improve print quality.