Abstract: An ink-jet printer includes a rotary drum 10, having a dielectric peripheral surface 11, for rotating at a constant speed, a sheet loader 90 for loading a sheet to the rotary drum 10, a sheet holding system for causing the sheet to be held on the peripheral surface 11 of the rotary drum 10, and a print head section 200 for printing an image on the sheet held on the peripheral surface 11 of the rotary drum 10 by jetting ink to the sheet while the rotary drum 10 makes a predetermined number of rotations. Particularly, the sheet holding system includes a charging section 20 and a supplementary charger section 26. The charging section 20 is charges the peripheral surface 11 of the rotary drum 10 on an upstream side of the loading point where the leading end of the sheet loaded by the sheet loader 90 contacts the peripheral surface 11 of the rotary drum 10. The supplementary charger section 26 charges the sheet to supplement the electrostatic attraction force attenuated during the rotation of the rotary drum 10.

Abstract: A head loading device includes a print head for ejecting ink from a print position adjacent to a paper sheet to print an image with the ink, and an elevator for moving the print head upward from the print position at the time of non-printing and downward to the print position at the time of printing. The head loading device further includes a three-point support mechanism for supporting, at three points, the print head moved to the print position by the elevator to hold the print head at a preset distance from the paper sheet.

Abstract: A head loading device includes a print head for ejecting ink from a print position adjacent to a paper sheet to print an image with the ink, and an elevator for moving the print head upward from the print position at the time of non-printing and downward to the print position at the time of printing. The head loading device further includes a three-point support mechanism for supporting, at three points, the print head moved to the print position by the elevator to hold the print head at a preset distance from the paper sheet.

Abstract: An ink-jet printer includes a sheet feed-in mechanism 60 for feeding a paper sheet, a rotary drum 10 having a peripheral surface 11 of a size larger than the paper sheet to be fed by the sheet feed-in mechanism 60, for rotating at a constant speed, a sheet holding system 20 for holding the paper sheet on the peripheral surface of the rotary drum, a print head 200 for printing an image by repeatedly ejecting ink onto the paper sheet held on the peripheral surface of the rotary drum 10 while the rotary drum 10 performs a predetermined number of rotations, a sheet separator 140 for separating the paper sheet from the peripheral surface 11 of the rotary drum, a sheet feed-out mechanism 160 for feeding out the paper sheet separated by the sheet separator 140, a control unit 111 for controlling the sheet feed-in mechanism 60, the rotary drum 10, the sheet holding system 20, the print head 200, the sheet separator 140 and the sheet feed-out mechanism 160.

Abstract: A nozzle unit is provided with nozzle heads of plural colors. Each nozzle head has a large number of ink-jet nozzles arranged side by side in the direction of main scanning. A head holder supports the nozzle unit in such a manner that the unit can move up and down between the printing position where printing is done on the printing sheet held on a rotating body and the non-printing position located above the printing position where the nozzle heads are maintained. The head holder is provided with a driving control circuit for driving the nozzle heads. The head holder, together with the nozzle unit, are movable vertically.

Abstract: An ink-jet printer includes a rotary drum 10, having a dielectric peripheral surface 11, for rotating at a constant speed, a sheet loader 90 for loading a sheet to the rotary drum 10, a sheet holding system for causing the sheet to be held on the peripheral surface 11 of the rotary drum 10, and a print head section 200 for printing an image on the sheet held on the peripheral surface 11 of the rotary drum 10 by jetting ink to the sheet while the rotary drum 10 makes a predetermined number of rotations. Particularly, the sheet holding system includes a charging section 20 and a supplementary charger section 26. The charging section 20 charges the peripheral surface 11 of the rotary drum 10 on an upstream side of the loading point where the leading end of the sheet loaded by the sheet loader 90 contacts the peripheral surface 11 of the rotary drum 10. The supplementary charger section 26 charges the sheet to supplement the electrostatic attraction force attenuated during the rotation of the rotary drum 10.

Abstract: An ink-jet printer includes an ink tank for storing ink, a print head for ejecting the ink supplied from the ink tank to print an image on a paper sheet moved relatively to the print head, an ink-amount sensing section for sensing that ink remaining in the ink tank is decreased to less than a reference amount to generate a sense signal, and a print control circuit for driving the print head such that images are printed on the number of paper sheets ordered by each print job except in a state where the sense signal is generated by the ink-amount sensing section. In particular, the print control circuit is arranged to continue a print job being executed at a time when the sense signal is generated by the ink-amount sensing section.

Abstract: An ink-jet printer includes a rotary drum for carrying a print sheet, a print head arranged above the rotary drum for printing an image by ejecting ink onto the print sheet, a washing board facing the print head to wash an end surface of the print head with ink ejected from the print head, and a control unit for controlling at a non-printing time the washing board to be set at a cleaning position located between the print head and the rotary drum and the print head to eject ink therefrom. Particularly, the washing board has grooves which receives an entire end surface of the print head and a drain section for draining the ink ejected from the print head and flowing in contact with the end surface of the print head within the groove section.

Abstract: An ink-jet printer, having a print head for jetting ink, an ink supply tube connecting between an ink tank and the print head, an ink supply pump interposing in the ink supply tube, an ink return tube connecting between and the print head and the ink tank, an ink return pump interposing in the ink return tube, a controller for controlling the ink supply pump and the ink return pump to fill the print head with ink in the ink tank, the volume of ink supplied by the ink return pump is greater than the volume of ink returned by the ink return pump in filling mode. Thus a foreign matter in the ink-jet nozzles of the print head can be cleaned by flowing out a foreign matter in the ink-jet nozzles.

Abstract: An ink-jet printer with an ink nozzle purging device includes a valve equipped in a portion of an ink supply pipe extending from a pump to a printing head unit, and an ink urging unit which has a chamber equipped in a portion of the pipe between the valve and the pump, and further has an elastic member disposed in the chamber. The member accumulates an elastic force by a pressure of the ink entering into the chamber while the pump is operated with the valve being closed, and then urges the ink toward the printing head unit when the valve is opened to release the elastic force accumulated in the elastic member.

Abstract: The ink-jet printer includes four ink tanks for detachably supporting four ink reserve bottles filled with inks of different colors and, for storing the inks respectively supplied from the ink reserve bottles, a print head having four nozzle units and connected to receive inks supplied from the ink tanks for printing a color image by ejecting the inks from the nozzle units onto a paper sheet, a lock system for locking each ink reserve bottle attached to a corresponding ink tank to prevent detachment from the corresponding ink tank, and a lock system controller for controlling the lock system.