Abstract: An inkjet printing device includes a printer, including an inkjet head having a nozzle configured to eject ink, an ink tank configured to store the ink, a circulation path configured to circulate ink between the ink tank and the inkjet head, an ink pump configured to send the ink from the ink tank to the inkjet head in order to circulate ink and an ink temperature detector configured to detect an ink temperature, a pressure regulator configured to apply a negative pressure to the ink tank and to regulate a pressure in the ink tank and a controller configured to control the pressure regulator in accordance with the ink temperature in the printer to regulate the pressure in the ink tank and to regulate a driving rate of the ink pump.

Abstract: A common air chamber is connected to an air layer of a pressurizing tank and to an air layer of a negative-pressure tank. A pressurizing-side communication valve opens/closes an air channel in an air conduit between the pressurizing tank and the common air chamber. A negative-pressure side communication valve opens/closes an air channel in an air conduit between the negative-pressure tank and the common air chamber. A negative-pressure tank atmospheric air opening valve switches the negative-pressure tank between a state shut off from the atmospheric air and a state open thereto. The pressurizing-side communication valve and the negative-pressure tank atmospheric air opening valve are of a normally-open type closed when electrified and open when not. The negative-pressure side communication valve is of a normally-closed type open when electrified and closed when not. While not electrified, a nozzle pressure of an inkjet head becomes a meniscus breakage pressure or less.

Abstract: An inkjet image forming apparatus includes inkjet heads each of which has two or more nozzle rows from which ink of different colors is injected (each of the nozzle rows includes nozzle holes), a wipe unit that includes wipers and carries out a wipe process to wipe away ink remained on a surface on which the nozzle rows are formed by the wipers, and a flush unit that carries out a flush process after the wipe process by injecting ink from nozzle holes into which ink of different color from color of ink that is injected from the nozzle holes flows during the wipe process. According to the apparatus, an amount of ink consumed in the flush process can be reduced and a replacement cycle of a mist-absorbing material for absorbing ink mists generated during the flush process can be prolonged.

Abstract: Upon supply of inks to second tanks of a plurality of printing units with the second tanks in communication with each other via a negative-pressure common air chamber in an air-tight state and with a negative-pressure force applied to the second tanks and the negative-pressure common air chamber, a controller is configured to drive ink supply units of the plurality of printing units to supply the inks such that times in which the inks flow into the second tanks in the plurality of printing units do not coincide with each other.

Abstract: When a face of a paper sheet to be discharged on which an image is formed faces downward, a paper discharge device divides an image region of image data on the paper sheet to be discharged into areas along a discharge direction, detects an area in which maximum image density for each divided area is higher than or equal to a specified threshold, and controls a discharge angle so that the detected area does not come into contact with a stacked paper sheet until the paper sheet to be discharged has been discharged from a discharge roller.

Abstract: A first ink air chamber is in communication with an air layer in a first ink tank for an ink of a first viscosity in communication with a first inkjet head. A second ink air chamber is in communication with an air layer in a second ink tank for an ink of a second viscosity in communication with a second inkjet head. A first on-off valve opens or closes communication between the first and second ink air chambers. A second on-off valve opens or closes communication between the second ink air chamber and the atmosphere. A pressure adjuster is configured to adjust a pressure in the second ink air chamber without intervention of the first ink air chamber. A controller is configured to drive the pressure adjuster to increase the pressure in the second ink air chamber with the first and second on-off valves being closed.

Abstract: A determiner determines whether a total ink amount in an ink circulation passage calculated by an ink amount calculator is less than an ink circulation necessary amount being an amount necessary for circulation of ink in the ink circulation passage, when a liquid level detector detects that a liquid level of the ink in an ink tank is lower than a liquid level corresponding to an ink circulation standard amount being a standard for ink circulation. A controller performs ink supply amount control to supply the ink from an ink bottle to the ink tank in such an amount that the total ink amount is kept below the ink circulation standard amount, when the determiner determines that the total ink amount is less than the ink circulation necessary amount.

Abstract: A controller temporarily opens a pair of side fence plates under a prescribed condition to move the side fence plates away from both side ends of sheets in a sheet width direction, after each time stacking of sheets at a first or second sheet stacking position is completed, but before a sheet receiving tray is temporarily lifted down to offset an offset guide plate and an end fence plate. Else, the controller sets an amount of lifting up and down of the sheet receiving tray such that the amount at the second sheet stacking position is smaller than that at the first sheet stacking position when offsetting the offset guide plate and the end fence plate after each time the stacking of sheets at the first or second sheet stacking position on the sheet receiving tray is completed.

Abstract: A first ink air chamber is in communication with an air layer in a first ink tank for an ink of a first viscosity in communication with a first inkjet head. A second ink air chamber is in communication with an air layer in a second ink tank for an ink of a second viscosity in communication with a second inkjet head. A first on-off valve opens or closes communication between the first and second ink air chambers. A second on-off valve opens or closes communication between the second ink air chamber and the atmosphere. A pressure adjuster is configured to adjust a pressure in the second ink air chamber without intervention of the first ink air chamber. A controller is configured to drive the pressure adjuster to increase the pressure in the second ink air chamber with the first and second on-off valves being closed.

Abstract: A sheet ejection device includes a sheet tray on which ejected sheets are stacked, a pair of side fences for restricting positions of the ejected sheets along a lateral direction perpendicular to an ejection direction, and at least one rib is formed vertically on each inner side of the side fences. The ribs are configured to contact with side edges of each of the ejected sheets while the each of the ejected sheets falls down to the sheet tray to align the ejected sheet along the lateral direction. The ejected sheets are aligned adequately by the ribs. According to the sheet ejection device, superior sheet ejection performance can be brought without affected by its environment.

Abstract: A determiner determines whether a total ink amount in an ink circulation passage calculated by an ink amount calculator is less than an ink circulation necessary amount being an amount necessary for circulation of ink in the ink circulation passage, when a liquid level detector detects that a liquid level of the ink in an ink tank is lower than a liquid level corresponding to an ink circulation standard amount being a standard for ink circulation. A controller performs ink supply amount control to supply the ink from an ink bottle to the ink tank in such an amount that the total ink amount is kept below the ink circulation standard amount, when the determiner determines that the total ink amount is less than the ink circulation necessary amount.

Abstract: An inkjet printer 1 includes an inkjet head 31 with nozzles for discharging ink, a pressurizer for pressurizing a route for ink supply to the inkjet head 31, a head driver 6 for driving the inkjet head 31, and a controller 8 operable for control the pressurizer to pressurize the route for a prescribed time to have fluxes of ink once spilt out of the nozzles and to render nozzles covered with spilt ink before use of the head driver 6 to drive the inkjet head 31 for discharge operation in a maintenance service to the inkjet head 31.

Abstract: A sheet ejection device includes a plurality of second sheet abutting members and a plurality of conductive members. Each second sheet abutting member has a non-conductive sheet regulating surface that abuts on a rear end portion in an ejecting direction of each sheet on a sheet output tray to regulate movement thereof. Each conductive member is attached at a position lower than a sheet drop height position and in the vicinity of each second sheet abutting member in a grounded state in the sheet width direction. Each conductive member attracts a rear end portion in the ejecting direction of a sheet on the uppermost layer of a plurality of sheets stacked on the sheet output tray, up to the sheet drop height position on the sheet regulating surface of the second sheet abutting member.

Abstract: A sheet transfer mechanism for a printer (100) to form an image on a sheet (10) being transferred in a transfer route by propelling ink at ink heads (110a), includes: a transfer belt (160) that has a plurality of adhesion through-holes (165) for holding a sheet (10) and transfers the sheet (10) being held thereon, a platen (620) that slidably supports the transfer belt (160) in an area facing the ink heads (110a) and has a plurality of suction through-holes (622) in an area through which the plurality of the adhesion through-holes (165) pass; a suction fan (650) that generates airflow with negative pressure for holding the sheet (10) on the transfer belt (160) through the plurality of the suction through-holes (622) and the plurality of the adhesion through-holes (165); and plugging plates (624) that adjust a number density of the suction through-holes (622) in the platen (620) depending on an arrangement of the ink heads (110a).

Abstract: An inkjet printer includes: a transfer path configured to transfer a recording medium therein: an inkjet head disposed with a gap from the transfer path, and configured to discharge ink toward the recording medium being transferred in the transfer path; a gap adjuster configured to adjust the gap; a guide disposed upstream of the inkjet head in a transfer direction of the recording medium, and configured to prevent the recording medium from being uplifted from the transfer path; and a guide mover configured to move the guide toward the inkjet head in the transfer direction in response to an increase in the gap by the gap adjuster.

Abstract: Provided is a control method for a computer system including one or more host computers, one or more storage systems, and a management computer. The storage system includes a plurality of controllers connected to the host computers through a network, and one or more logical volumes for storing data used by the host computers. At least one of the logical volumes is assigned to at least one of the controllers. According to the control method, when performance information of a controller exceeds a predetermined threshold, the logical volume assigned to the controller is assigned to another controller other than the controller. Thus, access loads on a storage system used in a network environment are balanced.

Abstract: A sheet ejection device includes a sheet tray on which ejected sheets are stacked, a pair of side fences for restricting positions of the ejected sheets along a lateral direction perpendicular to an ejection direction, and at least one rib is formed vertically on each inner side of the side fences. The ribs are configured to contact with side edges of each of the ejected sheets while the each of the ejected sheets falls down to the sheet tray to align the ejected sheet along the lateral direction. The ejected sheets are aligned adequately by the ribs. According to the sheet ejection device, superior sheet ejection performance can be brought without affected by its environment.

Abstract: A controller temporarily opens a pair of side fence plates under a prescribed condition to move the side fence plates away from both side ends of sheets in a sheet width direction, after each time stacking of sheets at a first or second sheet stacking position is completed, but before a sheet receiving tray is temporarily lifted down to offset an offset guide plate and an end fence plate. Else, the controller sets an amount of lifting up and down of the sheet receiving tray such that the amount at the second sheet stacking position is smaller than that at the first sheet stacking position when offsetting the offset guide plate and the end fence plate after each time the stacking of sheets at the first or second sheet stacking position on the sheet receiving tray is completed.

Abstract: A sheet ejection device includes a plurality of second sheet abutting members and a plurality of conductive members. Each second sheet abutting member has a non-conductive sheet regulating surface that abuts on a rear end portion in an ejecting direction of each sheet on a sheet output tray to regulate movement thereof. Each conductive member is attached at a position lower than a sheet drop height position and in the vicinity of each second sheet abutting member in a grounded state in the sheet width direction. Each conductive member attracts a rear end portion in the ejecting direction of a sheet on the uppermost layer of a plurality of sheets stacked on the sheet output tray, up to the sheet drop height position on the sheet regulating surface of the second sheet abutting member.

Abstract: A duplex printing machine 1 includes an inkjet head 27 with a piezoelectric element set for vibrations to propel out droplets of aqueous ink 50, an inkbottle 21 for supplying aqueous ink 50 to the inkjet head 27, a system of ink lines 28 having a lower tank 22, a circulation pump 23, a filter 25, and an upper tank 26, a degasser 24 having a degassing pump 24a for degassing flux of aqueous ink 50 being to be supplied to the inkjet head 27, and a controller 7 operable to control the degassing pump 24a, the controller 7 being adapted to operate, as a print time calculated from an image data set of a print job is equal to or greater than a prescribed value, for driving the degassing pump 24a to degas flux of aqueous ink 50.