Abstract: An inkjet printer includes a pair of temperature regulation modules mounted on opposite sides of each printhead in the printer. Each temperature regulation module includes a thermoelectric cooling device that is activated by a controller when the temperature of the printhead exceeds a predetermined setpoint. By cooling the printheads, the temperature of the printheads can be kept in a temperature range that enables fast drying inks to obtain their optimal performance and that prevents duplex printing operations from raising the temperature of the printheads significantly above the predetermined setpoint.

Abstract: A printing system comprises a printhead to eject ink through an opening in a carrier plate to a deposition region. A print medium is held against a movable support surface by vacuum suction communicated through platen holes of a vacuum platen and transported through the deposition region. An airflow control system comprises upstream and downstream valves associated with the printhead, individually addressable channels for the vacuum platen, or both. The upstream and downstream valves are arranged to selectively block and allow airflow through an upstream side or a downstream side, respectively, of the opening in the carrier plate. Actuation of the upstream and downstream valves may be controlled based on a location of the print medium. The channels are arranged to selectively control the supply of vacuum suction to respectively corresponding columns of platen holes. Actuation of the channels may be controlled based on a size of the print medium.

Abstract: A method of operating an inkjet printer operates solvent vapor generators that direct two flows of solvent vapor towards media on each side of each printhead in the process direction. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: Alignment apparatuses include a frame and contact elements connected to the frame. The contact elements contact items that are to be transported in a processing direction relative to the frame. The contact elements are in permeant fixed positions relative to the frame, and do not move relative to the frame. Adjustable mounts are connected to the frame and move the frame in the processing direction and in a perpendicular cross-processing direction. A controller is electrically connected to the adjustable mounts, and the controller is adapted to control the adjustable mounts to simultaneously move the frame and all the contact elements in the cross-processing direction and the processing direction while rotating the frame. Methods laterally shift imaging on sheets that have had rotational correction performed by such alignment apparatuses.

Abstract: A printing system comprises a printhead to eject a print fluid to a deposition region. Print media are held against a movable support surface via vacuum suction, and the movable support surface transports the print media through the deposition region. A vacuum plenum comprises a vacuum platen over which the movable support surface moves. The vacuum platen has platen holes that communicate the vacuum suction from the vacuum plenum to the movable support surface. An airflow restriction mechanism forms a high impedance zone in the vacuum platen, the high impedance zone comprising a subset of the platen holes. The airflow impedance through the high impedance zone is relatively high compared to the airflow impedance through another subset of the platen holes, which are part of a low impedance zone. The high impedance zone may be located near the printhead to reduce airflow through uncovered platen holes near the printhead.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus has a plurality of thermally insulative members that float in a volume of heat transfer lubricating fluid in which a X-Y translation mechanism moves to position a platform opposite an ejector. The apparatus also includes a housing having an internal volume in which the platform and X-Y translation mechanism are located. The heat transfer lubricating fluid can be a molten salt, such as a molten fluoride, chloride, or nitrate molten salt. The thermally insulative members can be spheres made of zirconium oxide or zirconium dioxide. The thermally insulative layer formed by the members floating in the fluid protects the X-Y mechanism while the housing helps keep the surface temperature of the object being formed on the platform in an optimal range for bonding of melted metal drops ejected from the ejector to a surface of a metal object being formed on the platform.

Abstract: A printing system comprises a printhead to eject a print fluid to a deposition region. A movable support surface, such as a belt, is used to transport print media through the deposition region, with the print media being held against the movable support surface by vacuum suction through holes in the movable support surface. A media registration device loads print media onto the movable support surface and registers the print media to a location of the movable support surface. The movable support surface comprises no-suction-regions in which the vacuum suction through the movable support surface is prevented. The no-suction regions extend across the width of the movable support surface in a cross-process direction and are arranged at predetermined intervals along the process direction. The control system causes the media registration device to register each of the print media relative to a respective one of the no-suction-regions.

Abstract: An inkjet printer includes solvent vapor generators that direct two flows of solvent vapor on each side of each printhead in the process direction toward media passing the printheads in the printer. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: An inkjet printer includes solvent vapor generators that direct two flows of solvent vapor on each side of each printhead in the process direction toward media passing the printheads in the printer. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a carrier plate and a printhead arranged to eject a print fluid through an opening of the carrier plate to a deposition region. The media transport device comprises a movable support surface to transport a print medium along a process direction through the deposition region, the media transport device holding the print medium against the movable support surface by vacuum suction. The air flow control system is arranged to selectively flow air through the opening of the carrier plate between the carrier plate and the printhead based on a location of a print medium transported by the media transport device relative to the printhead.

Abstract: A coefficient of friction (COF) sensor on a carrier roll surface wetted with fountain solution transferred from an imaging member measures COF of the wetted carrier roll surface in real-time, even between or during printing operations. The transferred fountain solution may be concentrated and/or chilled to solidify before the measurement. The measured COF is used in a feedback loop to actively control the fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during an imaging or other printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus has a thermally insulative layer between a platform on which an ejection head ejects drops of melted metal and a X-Y translation mechanism on which the platform is moved within an X-Y plane opposite the ejection head. The apparatus also includes a housing having an internal volume in which the platform and X-Y translation mechanism are located. In one embodiment, the thermally insulative layer is a plurality of spheres made of a thermally insulative material such as a ceramic made of zirconium dioxide or zirconium oxide. The thermally insulative layer protects the X-Y mechanism while the housing helps keep the surface temperature of the object being formed on the platform in an optimal range for bonding of the ejected melted metal drops to the object's surface.

Abstract: A method of operating a printer supplies an ink solvent or mixture of ink solvents to porous members positioned adjacent printheads. The ink solvent or solvent mixture evaporates from the porous members to provide a solvent vapor environment in the vicinity of the nozzle plates of the printheads. The solvent vapor environment attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with a magnetic field generator to form a magnetic field selectively about a nozzle from which melted metal drops are ejected. The drops ejected in the presence of the magnetic field have their velocities reduced from the initial velocity at which they are ejected. The reduced velocity increases the time in flight of the drops before they impact their landing areas. The increased travel time enables the melted metal drops to oxidize sufficiently that they bond less tightly than the drops ejected without passing through the magnetic field. Thus, the apparatus can form metal support structures that adhere less tightly to the part portions of the object so they can be more easily removed after printing of the object.

Abstract: A printing system comprises a printhead to eject a print fluid to a deposition region. Print media are held by vacuum suction against a movable support surface, which moves over a vacuum platen to transport the print media through the deposition region. The vacuum platen has platen holes through which the vacuum suction is communicated. Multiple vacuum plenums are provided to supply the vacuum suction to different groups of the platen holes. A first vacuum plenum is fluidically coupled to a first group of the platen holes located at least partially in the deposition region, and to a second group of platen holes located upstream of the first group. A second vacuum plenum is fluidically coupled to a third group of the platen holes comprising at least some platen holes located between the first and second groups of platen holes.

Abstract: A metal ejecting apparatus is disclosed. The metal ejecting apparatus includes a nozzle orifice in connection with the inner cavity and configured to eject one or more droplets of the liquid metal printing material, a float in contact with a surface of the liquid metal printing material, where the float is buoyant within the liquid printing material, and a filament attached to the float on a first end and attached to a level sensing system on a second end. The level sensing system may include an ultrasonic sensor, a visual sensor, a mechanical force sensor, a laser sensor, or a combination thereof. A method of sensing and controlling a level of liquid printing material in a metal jetting apparatus is also disclosed.

Abstract: A metal ejecting apparatus is disclosed. The metal ejecting apparatus includes a nozzle orifice in connection with the inner cavity and configured to eject one or more droplets of a liquid metal may include the metal printing material, and a first sensor pair in contact with an internal surface of a lower portion of the inner cavity. Each sensor pair is electrically connected to a printing material feed system where the printing material feed system is configured to receive an electrical signal indicative of an electrical connection from each sensor pair when the metal printing material bridges the electrical connection between each sensor in each sensor pair. A method of controlling level in a metal jetting apparatus is also disclosed.

Abstract: A method of operating a printer supplies an ink solvent or mixture of ink solvents to porous members positioned adjacent printheads. The ink solvent or solvent mixture evaporates from the porous members to provide a solvent vapor environment in the vicinity of the nozzle plates of the printheads. The solvent vapor environment attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: A method of automatically diagnosing media handling defects on sheets, the method including receiving a first image of a first sheet, determining that the first image includes a detected media handling defect, determining that the detected media handling defect matches one or more known media handling defects in a database, and displaying a rectifying action.

Abstract: A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a printhead to eject a print fluid through an opening of a carrier plate to a deposition region. The media transport device holds a print medium against the movable support surface by vacuum suction and transports the print medium through the deposition region. The air flow control system comprises an air supply unit to selectively flow air through the opening based on a location of a print medium relative to the printhead. The air supply unit comprises an air guide structure comprising an air outlet portion extending into the opening of the carrier plate between the printhead and the carrier plate, the air outlet portion terminating in an end wall that is angled obliquely relative to the movable support surface towards a reverse-process direction.