An image forming device includes an image carrier, a transfer device, a face-forming member, and a reducing element. The image carrier carries an image. The transfer device is disposed in contact with the image carrier, transports a recording medium, and applies a transfer voltage to a transfer region between the transfer device and the image carrier to transfer the image on the image carrier to the recording medium. The face-forming member is disposed in contact with a back face of the image carrier further upstream than the transfer region, is provided grounded along a direction intersecting the movement direction of the image carrier, and includes a conductive member forming a movement track face of the image carrier leading to the transfer region. The reducing element is provided on a current path going through the face-forming member, and reduces an amount of current leading from the face-forming member to ground.

An image forming apparatus includes an image forming section and a transfer section. The image forming section includes a first image forming unit that forms a first developer image and a second image forming unit that forms a second developer image. The transfer section transfers, on a basis of a first transfer condition, the first developer image onto a medium, and transfers, on a basis of a second transfer condition, the second developer image onto the medium onto which the first developer image has been transferred. The second transfer condition is different from the first transfer condition.

There is provided an image forming apparatus including a configuration in which a voltage of a polarity opposite to a toner charging polarity is applied. In the image forming apparatus, a guide region of a pre-transfer guide is located on a photosensitive drum side with respect to a common tangent line of a photosensitive drum and a development roller to reduce contamination of the pre-transfer guide and prevent contamination of recording materials.

A moving member is disposed between an upper guide, which guides a conveyed transfer material and to which a voltage is applied from a power source, and a lower guide, which guides the conveyed transfer material, the upper guide being disposed on an upstream side with respect to a photosensitive drum in a conveyance direction of the transfer material. The moving member is supported by the upper guide, and is capable of abutting against and separating from the lower guide. By being pushed by the transfer material, the moving member transitions from a first state in which the moving member is abutted against the lower guide to a second state in which the moving member is separated from the lower guide.

An image forming apparatus for forming an image on a recording medium, the image forming apparatus includes a discharge tray for supporting the recording medium, an internal unit disposed inside the apparatus main body, and a door serving as a part of outer surface members of the apparatus main body, the door being opened and closed to expose and cover an inside of the apparatus main body to the outside, wherein, by opening of the door, a fixing member that fixes the discharge tray to the apparatus main body is exposed to the outside, and removing of the fixing member from the apparatus main body allows the discharge tray to be detached from the apparatus main body without removing the outer surface members other than the door, and wherein detaching of the discharge tray from the apparatus main body allows the internal unit to be accessed.

The invention achieves uniform image quality for every transfer regardless of a moisture content on a surface of a paper sheet when a plurality of transfer processes is to be made on a single paper. A copier (1A) is provided with a optical sensor (20) which includes at least one light source, illuminates a paper sheet (P) with light, receives the light reflected from the paper sheet (P), and measures the received light intensity. Before each of a plurality of transfer processes, the copier (1A) calculates a moisture content on a surface of the paper sheet (P) from the light intensity measured by the optical sensor (20), and sets a transfer condition of a transfer device (15) based on the calculated moisture content on the surface of the paper sheet (P).

An image forming apparatus fixes a toner image on a transfer material at a fixing portion by applying an AC voltage from an AC power source to a fixing unit and includes a conductive pre-transfer guide on a position at which the transfer material nipped by a transfer portion and the fixing portion is in contact therewith. A capacitor and a Zener diode which is connected to the capacitor in parallel and maintains the pre-transfer guide at a predetermined voltage in a state in which a toner image is transferred to the transfer material nipped by the fixing portion and the transfer portion are arranged between the pre-transfer guide and the ground.

An image forming apparatus includes a transfer unit, a contact unit, and a constant-current controller. The transfer unit nips a recording medium using an image retaining unit and a transfer member and generates a transfer electric field in a transfer region therebetween so as to electrostatically transfer the image onto the recording medium. The contact unit is provided upstream and downstream of the transfer region in a recording-medium transport direction and comes into contact with the recording medium while the recording medium passes through the transfer region, so as to function as an electrode leading to a ground. The constant-current controller performs constant-current control on a transfer current to be fed to the transfer region by using a transfer voltage when the recording medium is a low-resistance recording medium having a predetermined resistance value or lower or having an electrically-conductive layer along a medium base surface.

An image forming device includes an image carrier carrying an image, a transfer device including paired transfer members that transport the image carrier and a recording medium, a grounded guide member that guides the recording medium to a transfer region, and a transfer power source that produces an electric field in the transfer region causing the image to be transferred onto the recording medium. The transfer power source includes a first transfer power source that imparts a first transfer voltage to one of the paired transfer members, and a second transfer power source that, when the recording medium has a predetermined resistance value or less, or is of low resistance having a conductive layer along a medium substrate face, imparts a second transfer voltage of opposite polarity and having an absolute value less than or equal to the first transfer voltage to the other of the paired transfer members.

A sheet conveyance apparatus includes a sheet conveyor configured to convey a sheet, a guide configured to form a conveyance path through which the sheet is conveyed by the sheet conveyor, and a sensor disposed on a same side as the guide with respect to the conveyance path. The guide includes a retracted portion disposed over a first region in a sheet width direction perpendicular to a sheet conveyance direction, the retracted portion being retracted with respect to a second region of the guide in the sheet width direction so as not to come into contact with the sheet passing through the conveyance path, the first region including a detection region of the sensor in the sheet width direction, the second region being a sheet passing region of the sheet in the sheet width direction excluding the first region.