Abstract: A coating system includes a leveling element and a dispenser assembly. The leveling element extends generally transverse to a substrate advance orientation and is releasably engageable against a substrate support. The dispenser assembly includes an array of side-by-side independent liquid dispensers and an air pressure assembly to supply a common air pressure to each dispenser to cause pressurized dispensing of a coating liquid from each dispenser onto a substrate on the substrate support. The liquid dispensing occurs at least during relative movement between the dispenser assembly and the substrate support and during the relative movement, the leveling element is actuated to uniformize the coating liquid on the substrate.

Abstract: Hard imaging devices and hard imaging device operational methods are described. According to one arrangement, a hard imaging device includes a pen adjacent to a first location of a media path and configured to eject a plurality of droplets of a liquid marking agent in a direction towards the media moving along the media path to form hard images using the media, the ejection of the droplets of the liquid marking agent from the pen creating aerosol droplets of the liquid marking agent, and a gas injection system adjacent to a second location of the media path which is downstream from the first location with respect to a direction of movement of the media along the media path, and wherein the gas injection system is configured to inject a gas towards the media.

Abstract: A charging assembly controls a selectable non-contact distance between a charge roller and an imaging surface.

Abstract: A charge roller includes a body having a metal external surface and an inorganic outer resistive coating.

Abstract: Printers, methods, and apparatus to form an image on a substrate are disclosed. An example disclosed charge roller includes a dielectric outer layer (104) comprising an inner surface (106) and an outer surface (108), the outer surface (108) to be charged by a first external surface and to discharge onto a second external surface, and the dielectric outer layer (104) to substantially prevent charge transfer between the inner surface (106) and the outer surface (108), and an electrically conductive inner layer (102) to direct electrical charge toward and away from the inner surface (106) of the outer layer (104), and to be coupled to an electrical source to control a transfer of the electrical charge.

Abstract: Ink jet printers, ink stream modulators, and methods to generate droplets from an ink stream are disclosed. An example method to generate droplets from an ink stream includes generating a stream of ink with an inkjet nozzle and modulating the stream of ink into a plurality of droplets by generating an alternating electrical field having a frequency based on a permittivity of the ink to cause a dielectrophoretic effect.

Abstract: Printers, methods, and apparatus to filter imaging oil are disclosed. An example apparatus to filter imaging oil, includes adjacent electrodes and a switching circuit. The example switching circuit selectively generates an electrostatic field between the adjacent electrodes to cause particles suspended in the imaging oil between the adjacent electrodes to adhere to at least one of the adjacent electrodes, and generates an alternating electric field between the adjacent electrodes to cause the particles to be detached from the adjacent electrodes.

Abstract: Apparatus, printers, and charge roller assemblies are disclosed. An example apparatus includes a roller to charge a printer surface when closer to the printer surface than an upper threshold, and a damper to reduce movement of the roller and to keep the roller closer to the printer surface than the upper threshold.

Abstract: Measurement devices, systems, and methods to measure a high field conductivity of a fluid are provided herein. The measurement device includes a fluid cell, a pair of electrodes, a voltage switch, and a measurement unit. The fluid cell is on an inclined plane to receive the fluid. The pair of electrodes are connected to the fluid cell. The pair of electrodes are spaced apart from one another to receive the fluid therebetween and positioned parallel to one another to pass an electrical current therethrough. The power unit provides a high voltage power supply to one electrode of the pair of electrodes. The measurement unit measures the electrical current that passes between the pair of electrodes through the fluid.

Abstract: Techniques related to printing using a metal-surface charging element. A printing system includes a metal-surface charging element and a power supply. The charging element is disposed to deposit electric charge on an imaging surface. The power supply may provide electric power with an alternating current (AC) component and a direct current (DC) component to the charging element.

Abstract: Techniques related to printing using a metal-surface charge element. A metal-surface charge element includes at least one metal charge roller to deposit electric charge on an imaging surface. Each metal charge roller includes a metal external surface in charge-transferring relation with the imaging surface and in a glow discharge regime during operation of the printing system for printing.

Abstract: Printer charging blades and printers are disclosed. An example charging blade for a printer includes an insulating layer to contact a photo imaging surface at an angle to apply pressure to the photo imaging surface, the pressure to control an amount of material present on the photo imaging surface, and a conductive layer attached to a side of the insulating layer, the conductive layer to be charged and to apply a first charge to the photo imaging surface.

Abstract: Printers, methods, and apparatus to reduce aerosol are disclosed. An example apparatus to reduce aerosol includes a print head to generate droplets and aerosol, and to direct the droplets toward a print substrate, a first corona wire to generate first ions having a first electrical polarity to direct the aerosol toward the print substrate, and a second corona wire to generate second ions to direct the aerosol toward the print substrate, wherein the second ions have a second electrical polarity that is opposite the first electrical polarity.

Abstract: Apparatus for capturing aerosols are disclosed. An example apparatus described herein includes a corona wire, and a nonconductive housing comprising a first cavity to expose a first portion of the corona wire, a second cavity to expose a second portion of the corona wire, and a chamber between the first and second cavities. A third portion of the corona wire is located within the chamber between the first and second portions of the corona wire.

Abstract: Apparatus, printers, and charge roller assemblies are disclosed. An example apparatus includes a roller to charge a printer surface when closer to the printer surface than an upper threshold, and a damper to reduce movement of the roller and to keep the roller closer to the printer surface than the upper threshold.

Abstract: A cleaning system usable with an image forming apparatus, which includes an intermediate transfer member having an image transfer blanket, includes a cleaning unit including a cleaner roller having at least one channel to transport fluid therein and a cleaner receiving surface to receive a cleaner layer, and a control unit including a temperature control module to control transportation of the fluid through the at least one channel to regulate a temperature of the cleaner roller, with the cleaner layer formed on the cleaner receiving surface to remove surface contaminants from the image transfer blanket.

Abstract: Printers, methods, and apparatus to form an image on a substrate are disclosed. An example disclosed charge roller includes a dielectric outer layer (104) comprising an inner surface (106) and an outer surface (108), the outer surface (108) to be charged by a first external surface and to discharge onto a second external surface, and the dielectric outer layer (104) to substantially prevent charge transfer between the inner surface (106) and the outer surface (108), and an electrically conductive inner layer (102) to direct electrical charge toward and away from the inner surface (106) of the outer layer (104), and to be coupled to an electrical source to control a transfer of the electrical charge.

Abstract: Printer charging blades and printers are disclosed. An example charging blade for a printer includes an insulating layer to contact a photo imaging surface at an angle to apply pressure to the photo imaging surface, the pressure to control an amount of material present on the photo imaging surface, and a conductive layer attached to a side of the insulating layer, the conductive layer to be charged and to apply a first charge to the photo imaging surface.

Abstract: Printers, methods, and apparatus to reduce aerosol are disclosed. An example apparatus to reduce aerosol includes a print head (102) to generate droplets (314-320) and aerosol (322-326), and to direct the droplets (314-320) toward a print substrate (104), a first corona wire (108) to generate first ions (340, 344) having a first electrical polarity to direct the aerosol (322-326) toward the print substrate (104), and a second corona wire (110) to generate second ions (340, 344) to direct the aerosol (322-326) toward the print substrate (104), wherein the second ions (340, 344) have a second electrical polarity that is opposite the first electrical polarity.

Abstract: An ink composition has controlled conductivity, and a digital printing system and a method of printing an ink employ an offset inkjet printing platform. The ink composition includes pigment particles dispersed in an oil-based dielectric carrier fluid with an oil-soluble dispersant. A concentration of dispersant is a fraction of a concentration of the pigment particles sufficient to render an electrical conductivity of the ink composition less than 100 pico Siemens per centimeter (pS/cm). The printing system includes an ink having an electrical conductivity less than or equal to about 300 pS/cm, an inkjet print head, a transfer medium, a developer, a remover and an image transferer. In the method of printing, the ink is nonelectrostatically jetted to the transfer medium, and developed into a fixed image. A portion of a supernatant is removed from the fixed image, and the fixed image is transferred to a media substrate.