Abstract: Devices include electrically conductive elements contacting a vacuum belt, and a voltage source connected to the electrically conductive elements. The electrically conductive elements form an electrical circuit from the voltage source, through the belt, and back to the voltage source. The electrically conductive elements are positioned so that they are separated from the belt when the belt moves the sheets of media between the electrically conductive elements and the belt. A processor is capable of identifying leading edges of the sheets of media on the belt (when voltage of the electrical circuit changes from a relatively higher voltage to a relatively lower voltage) and identifying trailing edges of the sheets of media on the belt (when the voltage of the electrical circuit changes from the relatively lower voltage back to the relatively higher voltage).

Abstract: A registration system for a printing device and a method for controlling the same are disclosed. For example, the registration system includes at least one sensor to detect a position of a print media, a platform comprising at least one multi-rotational wheel, and a processor communicatively coupled to the at least one sensor and the at least one multi-rotational wheel, wherein the processor calculates a desired movement of the at least one multi-rotational wheel based on the position of the print media.

Abstract: A three-dimensional object printer comprises a conveyor having a surface configured to convey a three-dimensional object in a first direction; and a leveling assembly configured to level a surface of the three-dimensional object as the conveyer conveys the three-dimensional object in the first direction, the leveling assembly comprising (i) a roller having a cylindrical shape, the roller having an outer surface that moves upon the surface of the three-dimensional object to level the surface of the three-dimensional object; and (ii) a guide device arranged between the roller and the planar surface of the conveyer, the device being configured to mechanically interact with the roller to maintain a constant distance between the outer surface of the roller and the planar surface of the conveyer.

Abstract: Devices include electrically conductive elements contacting a vacuum belt, and a voltage source connected to the electrically conductive elements. The electrically conductive elements form an electrical circuit from the voltage source, through the belt, and back to the voltage source. The electrically conductive elements are positioned so that they are separated from the belt when the belt moves the sheets of media between the electrically conductive elements and the belt. A processor is capable of identifying leading edges of the sheets of media on the belt (when voltage of the electrical circuit changes from a relatively higher voltage to a relatively lower voltage) and identifying trailing edges of the sheets of media on the belt (when the voltage of the electrical circuit changes from the relatively lower voltage back to the relatively higher voltage).

Abstract: A sheet registration system includes a transport member on which a sheet is conveyed in a process direction, a vacuum shuttle, and a feedback system. The vacuum shuttle includes a vacuum head which applies suction to the sheet and actuators for rotating the vacuum head in a plane parallel to a plane of the transport member and translating the vacuum head in a cross-process direction. In response to feedback instructions generated by the feedback system, the actuators move the vacuum head, relative to the transport member, while the vacuum is applied to the sheet. The sheet registration system is suitable for use in a printer for reducing skew and lateral offset of sheets of print media.

Abstract: Both the inboard and outboard fluffer nozzles of a top vacuum corrugation feeder are configured to allow adjustability in angle of air flow. This is to allow the direction of the air to be angled more towards the lead edge or trail edge of a top few sheets in a stack of specialty sheets. The fluffer nozzles are also adjustable in a horizontal plane for positioning at desired locations along the sheet stack. This allows the air to overcome barriers created by the design of specialty media that would otherwise trap the air and prevent it from being distributed between sheets. The cross-section of the nozzles is also adjustable, providing a smaller or wider throat in order to allow the air velocity to be optimized to best separate the sheets in problem areas.

Abstract: A sheet stacking system is disclosed that has improved tolerance for sheets that are not flat. Successive sheets are aligned onto a stack by a plurality of registration belts. The heights of the pivoting registration belts are compared with one another to determine the unevenness of the top of the stack. This unevenness is represented by the difference between the heights of the highest and lowest registration belt ?stack-height and is monitored to quantify the planarity of the top of the stack. When the unevenness (?stack-height) exceeds a threshold, the system switches to a modified method to control the elevation of the stack. This method may include stopping the machine from stacking before the unevenness is too large for the registration belts to uniformly drive sheets. This invention prevents the stacker from attempting to stack when sheets are expected to skew thereby preventing jams and unusable stacks.

Abstract: A three-dimensional object printer comprises a conveyor having a surface configured to convey a three-dimensional object in a first direction; a leveling assembly configured to level a surface of the three-dimensional object as the conveyer conveys the three-dimensional object in the first direction, the leveling assembly comprising (i) a member, (ii) a roller connected to the member having a cylindrical shape, the roller having an outer surface that moves upon the surface of the three-dimensional object to level a surface of the three-dimensional object, and (iii) an actuator arranged near the member, the actuator being configured to mechanically interact with the member to move the roller with respect to the planar surface of the conveyer; and a controller configured to, as the outer surface of the roller moves upon the surface of the three-dimensional object, operate the actuator to move the roller with respect the conveyer.

Abstract: A three-dimensional object printer comprises a platen, an ejector head having a plurality of ejectors configured to eject drops of material toward the platen, a sensor configured to measure heights of drops of material ejected onto the platen, and a controller operatively connected to the sensor and the ejector head. The controller is configured to operate the plurality of ejectors to eject drops of material toward the platen to form a first layer of material upon the platen; operate the sensor to measure a height profile of the first layer of material; and operate the plurality of ejectors to eject drops of material toward the platen to form a second layer of material upon the first layer of material with reference to the measured height profile.

Abstract: A three-dimensional object printer comprises a conveyor having a surface configured to convey a three-dimensional object in a first direction; a leveling assembly configured to level a surface of the three-dimensional object as the conveyer conveys the three-dimensional object in the first direction, the leveling assembly comprising (i) a member, (ii) a roller connected to the member having a cylindrical shape, the roller having an outer surface that moves upon the surface of the three-dimensional object to level a surface of the three-dimensional object, and (iii) an actuator arranged near the member, the actuator being configured to mechanically interact with the member to move the roller with respect to the planar surface of the conveyer; and a controller configured to, as the outer surface of the roller moves upon the surface of the three-dimensional object, operate the actuator to move the roller with respect the conveyer.

Abstract: A three-dimensional object printer comprises a conveyor having a surface configured to convey a three-dimensional object in a first direction; and a leveling assembly configured to level a surface of the three-dimensional object as the conveyer conveys the three-dimensional object in the first direction, the leveling assembly comprising (i) a roller having a cylindrical shape, the roller having an outer surface that moves upon the surface of the three-dimensional object to level the surface of the three-dimensional object; and (ii) a guide device arranged between the roller and the planar surface of the conveyer, the device being configured to mechanically interact with the roller to maintain a constant distance between the outer surface of the roller and the planar surface of the conveyer.