Abstract: There is disclosed a color image forming apparatus, which makes it possible to prevent a reproduced image from generating image defects, such as a color unevenness, a toner scattering, etc.

Abstract: A color image forming apparatus includes plural developing units that respectively form toner images of different colors on plural photoreceptors, plural primary transferring devices that successively transfer each of the toner images of the plural photoreceptors onto an intermediate transfer belt, which holds a color toner image transferred and superimposed by primary transfer, a secondary transferring device that transfers concurrently the color toner image onto a transfer material, a drive roller that drives the intermediate transfer belt and that is placed between one of the plurality of primary transferring devices which is arranged on the most downstream side in the direction of movement of the intermediate transfer belt and the secondary transferring device, and a controller that controls a discharger discharging the color toner image and the drive of the drive roller.

Abstract: A color image forming apparatus includes primary transferring units that conduct the successive primary transfer onto an intermediate transfer body on which each of toner images different colors of the photoreceptors has been formed, a secondary transferring unit that transfers a color toner image formed by superimposing on the intermediate transfer body onto a transfer material, a pre-charging unit placed downstream of the primary transferring units and upstream of the secondary transferring unit and that applies electric charge to the color toner image on the intermediate transfer body before the secondary image transfer with the polarity of the applied electrical charge identical to polarity of the potential of the toner, and a potential adjustment unit placed downstream of the pre-charging unit and upstream of the secondary transferring unit, and applied an electric charge that has a polarity opposite to that of the potential of the toner to the color toner image on the intermediate transfer body.

Abstract: There is described an image forming apparatus, which makes it possible to conduct a sufficient discharging operation for a toner image. The apparatus includes an image forming section, an image bearing member, an intermediate transfer belt, a part of which is supported in a state of a flat plane by supporting members, a primary transferring device to transfer a toner image from the image bearing member onto the intermediate transfer member, a secondary transferring device to transfer the toner image onto a transfer material, a scorotron discharging device that is disposed at an upstream side of the secondary transferring device, where the part of the intermediate transfer member is supported in the state of the flat plane, and includes a discharging electrode and a grid to discharge the toner image; and a conductive brush that opposes to the scorotron discharging device and contacts the rear surface of intermediate transfer member.

Abstract: Disclosed is an image forming apparatus that comprises: an image bearing member; an image forming unit for forming a toner image on the image bearing member; an intermediate transfer member; a first transfer device for transferring the toner image on the image bearing member onto the intermediate transfer member; a second transfer device for transferring the toner image on the intermediate transfer member onto a transfer material; an intermediate transfer member cleaner for cleaning the intermediate transfer member after the transfer; a charging unit for giving the electric charge to the intermediate transfer member; and a control unit by which, when the charging unit is controlled, in non-image area on the intermediate transfer member, the intermediate transfer member is charged to the reverse polarity to the charge of toner, and the toner adhered to the second transfer device is transferred to the intermediate transfer member.

Abstract: An image forming apparatus including: an image forming section for forming a toner image with toner particles having a first electric polarity; an intermediate transfer body; a first transfer section for transferring the toner image to the intermediate transfer body; a second transfer section for transferring to a recording medium; a charger for applying charges to the toner image on the intermediate transfer body before transferring, the charger having a discharge electrode and a grid; and a charge control section for applying a first voltage and a second voltage to the discharge electrode and the grid, respectively, the first voltage having a polarity reversed from the first electric polarity, the second voltage having an potential between a surface potential of the intermediate transfer body where no toner particle is adhered and a second surface potential of a portion where toner particles are maximally adhered.

Abstract: In an image forming apparatus, an electrostatic latent image is reverse-developed by a developing device with a development bias applied, through conveying a two-component developer layer containing toner particles having a volume-average particle diameter of 3 to 5 &mgr;m by a developer carrying member rotatably provided, a developed toner image is transferred onto a recording medium or an intermediate transfer body, and untransferred toner particles remaining on an image forming body having passed a transfer region are removed by a cleaning member provided in pressure contact with the surface of the image forming body. The length in an axis direction of the image forming body of an useless toner image formed on the image forming body at the starting time and the ending time of an image formation sequence denoted by L, the total charge quantity of the toner particles making up the useless toner image is 0.04L &mgr;C or less.

Abstract: It is an object of the present invention to provide a backlight unit capable of improving the utilization efficiency of light. A backlight 10 includes a light source 13, a light guide plate 12 for introducing light emitted from the light source 13 from an incidence surface 12a provided on an end and for emitting the light from one surface, a diffusive reflector 15 provided such that the surface having a minute concavo-convex portion 15d faces the other surface of the light guide plate 12, and a light directivity control sheet 17 provided on the one surface of the light guide plate 12 such that the apexes 17c of pyramid-shaped objects 17b face the opposite side to the light guide plate 12.

Abstract: An image forming apparatus is provided for obtaining excellent developing properties using toner with small particle diameters and for forming high-quality visual images. In a developing device of an image forming apparatus, a two-component developer is used which satisfies conditions that volume mean particle diameter dt of a toner is 3˜5 &mgr;m (Condition 1), volume mean particle diameter dc of a carrier is 5 dt˜10 dt (Condition 2), and a weight ratio Rw of the toner and the carrier is 1.6 (dt/dc) ×(&rgr;t/&rgr;c)˜2.4 (dt/dc)×(&rgr;t/&rgr;c) (Condition 3, where &rgr;t and &rgr;c are density of the toner and the carrier, respectively). A main magnetic pole M of a rotary sleeve is arranged in the vicinity of the closest position of the rotary sleeve and an image forming body, and the closest distance D between the rotary sleeve and the image forming body satisfies a condition that D is 0.5 H˜0.8 H for the free tip height H of a magnetic brush B of the main magnetic pole M.

Abstract: A pasting and bookbinding method in which a leading edge of a sheet conveyed in a first conveying path having a sheet conveyor is brought into contact with a hitting member and the sheet skew is corrected, a linear paste coating portion is formed by a paste jetting device in the vicinity of a side edge portion of the sheet conveyed in a second conveying path in a direction perpendicular to the first conveying path, and plural sheets after the paste coating processing are stacked on a sheet stacking table provided below the second conveying path, and aligned by an aligner, and the linear pasted portion is pressed by a pressing device, and after a pasted booklet is produced, the booklet is delivered onto the delivery tray provided in the conveying direction downstream of the first conveying path and on an outside side surface of the apparatus.

Abstract: In an image forming apparatus, an electrostatic latent image is reverse-developed by a developing device with a development bias applied, through conveying a two-component developer layer containing toner particles having a volume-average particle diameter of 3 to 5 &mgr;m by a developer carrying member rotatably provided, a developed toner image is transferred onto a recording medium or an intermediate transfer body, and untransferred toner particles remaining on an image forming body having passed a transfer region are removed by a cleaning member provided in pressure contact with the surface of the image forming body. The length in an axis direction of the image forming body of an useless toner image formed on the image forming body at the starting time and the ending time of an image formation sequence denoted by L, the total charge quantity of the toner particles making up the useless toner image is 0.04L &mgr;C or less.

Abstract: An image forming apparatus is provided for obtaining excellent developing properties using toner with small particle diameters and for forming high-quality visual images. In the developing device of the image forming apparatus, a two-component developer is used which satisfies conditions that volume mean particle diameter dt of the toner is 3˜5 &mgr;m (Condition 1), volume mean particle diameter dc of the carrier is 5dt˜10dt (Condition 2), and a weight ratio Rw of the toner and the carrier is 1.6 (dt/dc)×(&rgr;t/&rgr;c)˜2.4 (dt/dc)×(&rgr;t/&rgr;c) (Condition 3, where &rgr;t and &rgr;c are density of the toner and the carrier, respectively). A main magnetic pole of a rotary sleeve is arranged in the vicinity of the closest position of the rotary sleeve and the image forming body, and the closest distance D between the rotary sleeve and the image forming body satisfies a condition that D is 0.5 H˜0.8 H for the free tip height H of a magnetic brush of the main magnetic pole.

Abstract: A pasting and bookbinding method in which a leading edge of a sheet conveyed in a first conveying path having a sheet conveyor is brought into contact with a hitting member and the sheet skew is corrected, a linear paste coating portion is formed by a paste jetting device in the vicinity of a side edge portion of the sheet conveyed in a second conveying path in a direction perpendicular to the first conveying path, and plural sheets after the paste coating processing are stacked on a sheet stacking table provided below the second conveying path, and aligned by an aligner, and the linear pasted portion is pressed by a pressing device, and after a pasted booklet is produced, the booklet is delivered onto the delivery tray provided in the conveying direction downstream of the first conveying path and on an outside side surface of the apparatus.

Abstract: A developing device has a developing unit to develop an electrostatic latent image formed on an image carrier surface with two-component developer composed of toner and carrier, a toner recycling device to feed toner removed from the image carrier surface by a cleaner back to the developing unit so as to recycle the removed toner, a supply member for supplying fresh toner to the developing device, and a toner concentration controller to control toner concentration in accordance with the result of a comparison between a reference signal that has been set, and a toner concentration of developer determined when the magnetic permeability of developer is detected by a toner concentration detection sensor disposed in the developing device. A drive source of the developing unit and that of the toner recycling device can be individually controlled.