Abstract: An optical deflector, a method of producing the optical deflector, an optical scanning device, and an image forming apparatus are disclosed that are able to save resources, provide high reliability at low cost, and enable stacked and relatively-offset polygon mirrors to be arranged precisely. The optical deflector includes a rotary member supported by a bearing with plural polygon mirrors fixed thereon. The polygon mirrors are stacked along a rotation axis of the rotary member, the polygon mirrors are relatively offset by a predetermined angle in a rotation plane of the rotary member, and an effective deflection area of each of the reflection surfaces of any one of the polygon mirrors is positioned away from a center of the corresponding reflection surfaces of the other one of the polygon mirrors in the direction of the rotation axis.

Abstract: In a stencil printing apparatus capable of duplex printing, in which a front surface printing process for printing a front surface image on one surface of a sheet of paper fed by a sheet feeding unit is performed, the sheet is re-fed to sheet re-feeding means, and then a rear surface printing process for printing a rear surface image on the other surface is performed, the positions of the front surface image and rear surface image to be printed on the sheet can be moved together. The stencil printing apparatus comprises: a printing unit having a printing cylinder and pressing means; the sheet feeding unit for feeding the sheet toward the printing unit; and the sheet re-feeding means for temporarily accommodating the sheet after a printed image is formed on the front surface thereof in the printing unit, and then re-feeding the sheet toward the printing unit.

Abstract: A water-in-oil emulsion ink comprises a water phase and an oil phase, wherein the water phase comprises a carbon black pigment having a pH of less than 8 dispersed therein by a water-soluble resin, and wherein the water phase also comprises a pH-adjusting agent to achieve a pH value for the water phase of 8 or greater. The ink maintains stable rheology on ageing, and provides a stable and consistent ink detection signal even after periods of non-use.

Abstract: A printing system including a plurality of different kinds of printers and a printer selecting device therefore are disclosed. The printer selecting device includes an accepting section for accepting information representative of a desired number of printings input, and selecting means for selecting one of the printers matching with the desired number of printings. Image data to be printed are sent from the printer selecting device to the printer selected. In this configuration, one printer adequate for the desired number of printings, which is an important factor for the selection of a printer, is automatically selected.

Abstract: A double-sided printing apparatus using a double sided printing with one plate cylinder and one pressing means system, that is capable of carrying out double-sided printing simply and at low cost, with little deviation in the position of the printed image and with satisfactory resist. Printed matter with little deviation of the image position with respect to the sheet position and with good resist can be obtained, by eliminating delay in feeding sheets due to slippage between roller and press roller by operating the transport belt on the upstream side, and so on, and by eliminating resistance during sheet transportation due to contact with the guide member provided along the circumferential surface of the press roller, when pressing sheets against the press roller with a roller or the like, and transporting the sheets along the guide member or the like provided along the peripheral surface of the press roller.

Abstract: A stencil printing apparatus allows printing on coated paper as in ordinary paper (uncoated paper), and can make a contribution to the diversification of printing needs. The stencil printing apparatus comprises a printing apparatus body comprising a printing drum having UV curable ink, and an UV irradiation device connected to a paper output unit of the printing apparatus body. When the paper type is recognized as coated paper on the basis of a signal from paper type input means or the like, control means controls a master-making energy supplied to a thermal head serving as master-making means, to be larger than a master-making energy supplied in the case of uncoated paper. The paper onto which an ink image corresponding to the characteristics of coated paper has been transferred is then fed into the UV irradiation device, where the ink is dried and cured.

Abstract: A printing method and a printing apparatus including a stencil printing apparatus and so on. Focusing on the relationship that exists between copy number and master position displacement that occurs during printing, by determining by pretest and setting top-bottom shift correction values in accordance with parameters including copy number that affect printed master position displacement in the direction of rotation of a plate cylinder, and during printing, utilizing conventionally used top-bottom shift means to automatically execute top-bottom shift correction in accordance with the set top-bottom shift correction values, printing position displacement can be prevented from occurring, waste of master and printing medium such as paper can be eliminated and, in addition, the operation time can be shortened and the number of operation steps can be reduced.

Abstract: Disclosed is a polygon mirror scanner device, used as a rotor, having a plurality of mirror faces on the outer peripheral face of a mirror member having a substantially tubular shape, with a tubular magnet adhered to the lower inner peripheral face of the mirror member. A depression is uniformly formed in the circumferential direction on the inner peripheral face, at a position opposite the mirror faces, such that a gap forms between the magnet and the inner peripheral face when the magnet is at a predetermined positioned. An adhesive agent is provided at the upper end and lower end of the magnet, but not in the gap. When the mirror faces are two-tiered, the upper end of the magnet is located at substantially an intermediate position in the height direction of the two-tier mirror faces.

Abstract: A duplex printing apparatus capable of printing by performing a slow-up operation on the printing speed so that it increases from a low speed to a set speed at the time of duplex printing. Control means controls, on the basis of a drum rotation position signal and a drum speed signal from a home position sensor and an unshown encoder sensor, a sheet feeding unit, printing unit, sheet discharge unit, sheet re-feeding means and switching member, such that the printing speed (drum speed) slows up from a low speed to a set speed in each rotation of a plate cylinder, which corresponds to feeding of each sheet to the printing unit when duplex printing is started, and further controls a stepping motor of the sheet re-feeding means such that conveyance speed of a sheet receiving board synchronizes with the printing speed.

Abstract: To provide an active energy beam-curable ink for screen printing, having at least monomer components and a polymerization initiator, wherein the polymerization initiator has an absorbance in terms of the concentration thereof of 100 or less at 365 nm.

Abstract: To provide an active energy beam-curable ink which includes active energy beam-curable monomer components, wherein at least one of the active energy beam-curable monomer components contains a unit represented by the following structural formula (1) in its molecule.

Abstract: An image forming apparatus of the present invention includes a stencil printer section and a non-stencil printer section and can form a stencil image and a non-stencil image on a single sheet. A first and a second adjusting section respectively adjusts the position of the stencil image and that of the non-stencil image relative to the sheet in the direction of sheet conveyance and the widthwise direction of the sheet perpendicular to the direction of sheet conveyance. A first shift display section displays an amount of shift of the position adjusted by the first adjusting section. A first moving mechanism shifts the position of the stencil image in accordance with the operation of the first adjusting section. A second shift display section displays an amount of shift of the position adjusted by the second adjusting section. A second moving mechanism shifts the position of the non-stencil image in accordance with the operation of the second adjusting section.

Abstract: A stencil printer includes at least an upstream and a downstream printing section, as seen in the direction of sheet conveyance, each including a print drum and a press roller for pressing a sheet against the print drum. An intermediate conveyor, positioned between the upstream and downstream printing sections, conveys the sheet from the former toward the latter. A dual master, formed with a first and a second image, is wrapped round the print drum of the upstream printing section. This printing section includes a refeeding device, a path selector, and a switching device.

Abstract: A stencil printer of the present invention includes a print drum and a pressing member selectively movable into or out of contact with the print drum. A duplex master, formed with a first and a second image in the lengthwise direction thereof, or a simplex master formed with a third image is wrapped around the print drum in a duplex mode or a simplex mode, respectively. The stencil printer is capable of selectively performing a duplex print mode operation, which consists of a front printing step and a rear pining step following the front printing step, or a simplex print mode operation. When the operator of the printer selects the duplex print mode to cause the duplex master to be wrapped around the print drum and then replaces the duplex print mode with the simplex print mode, the stencil printer produces an alarm and inhibits the simplex pint mode operation from being started.

Abstract: Provided is a bulk paper feeding device with an intermediate conveyor comprising a carrier capable of carrying a large quantity of paper, a paper feeding mechanism for picking up and feeding one sheet at a time of the paper from the carrier, and an intermediate conveyor for transporting a sheet of paper fed from the feeding mechanism to the main paper feeding table of the paper feeder on the body of the image forming device or to the vicinity of a paper feeding port that faces the main paper feeding means of the paper feeder.

Abstract: A printer is capable of simply carrying out image division printing (repeat printing), and capable of reducing the number of images that are unusable due to clipping of the image on the leading edge of the sheet. The printer has an image division printing function of forming a plurality of print images on a single sheet, and comprises: an image reading unit that reads document images; a plate making unit that makes master plates; a printing unit having a cylinder around which a master made in the plate making unit is wound, and a pressure member that presses sheets against the cylinder; and a sheet supply unit that supplies sheets to the printing unit.

Abstract: A water-in-oil emulsion ink comprises a water phase and an oil phase, wherein the water phase comprises a carbon black pigment having a pH of less than 6. The emulsion ink maintains stable rheology on ageing.

Abstract: A sheet storage device improved in terms of its performance in aligning sheets discharged from an image forming apparatus. In the sheet storage device, a plate-like shock absorber is superimposed on a surface of a fence member forming an end fence, and a lower end portion of the shock absorber is fixed to the fence member, with an intermediate portion thereof being curved so as to be convex and an upper end portion thereof being movably engaged with an engagement portion formed at an upper end of the fence member. In the intermediate portion, a spacer is provided between the fence member and the shock absorber to form a gap between the shock absorber and the fence member at a position where the shock absorber is hit by the sheets.

Abstract: In an ultraviolet ray irradiation apparatus capable of forestalling printed material jams between a paper discharge unit of a printing apparatus and a reception unit of the ultraviolet ray irradiation apparatus, a signal line for exchanging electric signals with the printing apparatus is provided, and control is performed such that rotational driving of a paper conveyance belt of the ultraviolet ray irradiation apparatus is begun upon reception of a printing drum rotation start signal or a paper feeding unit paper conveyance start signal, and the rotational driving of the belt is halted after a predetermined amount of time has elapsed following reception of a printing completion signal.

Abstract: A stencil printing apparatus which suppresses master consumption by switching between simplex printing using a simplex master and single-step duplex printing using a duplex master automatically in accordance with master information and sheet information comprises a printing drum and pressing means, and can be made to switch between duplex printing, in which a rear surface printing step is performed after a front surface printing step, and simplex printing by wrapping a duplex master formed with a first engraved image and a second engraved image around the printing drum during duplex printing, and wrapping a simplex master formed with a third engraved image for simplex printing around the printing drum during simplex printing.