Abstract: An image forming apparatus includes a nip forming member and a transfer bias output device that outputs a transfer bias to form a transfer electric field in a transfer nip between the nip forming member and an intermediate transfer member. Upon transfer of a composite toner image including a particular toner image onto a recording medium in the transfer nip, the transfer bias output device outputs the transfer bias including a first superimposed bias in which a direct current (DC) component is superimposed on an alternating current (AC) component. Upon transfer of the composite toner image without the particular toner image onto the recording medium in the transfer nip, the transfer bias output device outputs one of the transfer bias including a second superimposed bias having a peak-to-peak value of the AC component smaller than that of the first superimposed bias and the transfer bias including only the DC component.

Abstract: An image forming apparatus including an image forming device, a transfer device, a fixing device, an inverting device, and a processor. The transfer device includes an intermediate transfer member, a nip forming member, and an electric potential difference generator to generate an electric potential difference between the intermediate transfer member and the nip forming member. The processor causes the electric potential difference generator to generate a first electric potential difference containing only a DC component when a toner image is transferred onto a first side of a recording sheet, and to generate a second electric potential difference containing a DC component and a superimposed AC component when the toner image is transferred onto a second side of the recording sheet. The second electric potential difference has an averaged absolute value per unit of time smaller than an absolute value of the first electric potential difference.

Abstract: A belt device incorporatable in an image forming apparatus includes an endless belt, multiple belt tension rollers disposed in contact with an inner surface of the endless belt, a rotary cleaning member to contact a belt wound area of the endless belt facing an opposing roller to form a cleaning nip between the rotary cleaning member and the endless belt and rotate the rotary cleaning member in a direction opposite the belt moving direction within the cleaning nip, and a voltage applier. The cleaning nip is formed by offsetting a center of the cleaning nip upstream from a center of the belt wound area of the endless belt in the belt moving direction and by at least contacting the rotary cleaning member in a range from the belt wound area to a tensioned belt area located upstream from the belt wound area in the belt moving direction.

Abstract: A transfer device includes a rotatable image bearing member to bear a toner image on a surface thereof, a nip forming member to contact the surface of the image bearing member, and a bias output device to output a bias current to alternately form a transfer-direction electric field to transfer toner charged with a normal polarity in a toner image formed on the image bearing member to move therefrom to a recording medium and a return-direction electric field to return the toner from the recording medium to the image bearing member. A transition time T1 from a first time at which a current for forming the transfer-direction electric field reaches its maximum (It) to a second time at which a current for forming the return-direction electric field reaches its maximum (Ir) is longer than a transition time T2 from the second time to the first time.

Abstract: A belt tracking system for adjusting displacement of a movable belt in an axial direction of a plurality of rollers about which the movable belt is entrained includes a slope member and a roller shaft support. The slope member is disposed at least at one end of at least one of the plurality of rollers in the axial direction, to tilt the roller due to movement of the belt. The roller shaft support rotates about a predetermined shaft and includes a shaft recovery member to recover a tilt of the slope member. The shaft recovery member is disposed within a shortest circumference of a closed curve among closed curves within which the slope member and the roller shaft support are disposed in a state in which the roller shaft support is rotated.

Abstract: A cleaner is provided. The cleaner includes a cleaning blade having an edge to be contacted with a surface of a member to be cleaned while moving relative to the member to clean the surface of the member. The cleaning blade includes the edge, and first and second side surfaces, wherein the edge is disposed between the first and second side surfaces. When the cleaning blade is not contacted with the surface of the member to be cleaned, the first side surface is opposed to the surface of the member, and when the cleaning blade is contacted with the surface of the member, the edge, and the first and second side surfaces of the cleaning blade are contacted with the surface of the member.

Abstract: A belt tracking system for adjusting misalignment of a movable belt in an axial direction of a plurality of rollers about which the movable belt is entrained includes a slope member and a stationary shaft guide. The slope member is disposed at both ends of at least one of the plurality of rollers in the axial direction, to tilt the roller as the belt moves in the axial direction. The stationary shaft guide contacts the slope member. A distance between a contact point of the slope member that contacts the stationary shaft guide and an end portion of the slope member in the axial direction is longer than a maximum traveling distance that the slope member travels in the axial direction.

Abstract: An image forming apparatus includes an image carrier to carry a toner image, a transfer member to form a transfer nip by contacting the image carrier surface, and a power supply to output a voltage to the recording material captured in the transfer nip so as to transfer the toner image formed on the image carrier surface. The voltage is switching alternately between a voltage in the transfer direction and a voltage opposite to the voltage in the transfer direction, and a time average value (Vave) of the voltage is set to have a polarity of the transfer direction, and is set to a value in the transfer voltage side, and a change mode to change a cycle of the voltage output from the power supply can be changed based on the toner deterioration information which determines the deterioration status of the toner.

Abstract: A belt device incorporatable in an image forming apparatus includes an endless belt, multiple belt tension rollers disposed in contact with an inner surface of the endless belt, a rotary cleaning member to contact a belt wound area of the endless belt facing an opposing roller to form a cleaning nip between the rotary cleaning member and the endless belt and rotate the rotary cleaning member in a direction opposite the belt moving direction within the cleaning nip, and a voltage applier. The cleaning nip is formed by offsetting a center of the cleaning nip upstream from a center of the belt wound area of the endless belt in the belt moving direction and by at least contacting the rotary cleaning member in a range from the belt wound area to a tensioned belt area located upstream from the belt wound area in the belt moving direction.

Abstract: A belt device incorporatable in an image forming apparatus includes an endless belt, multiple belt tension rollers disposed in contact with an inner surface of the endless belt, a rotary cleaning member to contact a belt wound area of the endless belt facing an opposing roller to form a cleaning nip between the rotary cleaning member and the endless belt and rotate the rotary cleaning member in a direction opposite the belt moving direction within the cleaning nip, and a voltage applier. The cleaning nip is formed by offsetting a center of the cleaning nip upstream from a center of the belt wound area of the endless belt in the belt moving direction and by at least contacting the rotary cleaning member in a range from the belt wound area to a tensioned belt area located upstream from the belt wound area in the belt moving direction.

Abstract: An image forming apparatus includes a rotatable image bearer, a charging member to contact a surface of the image bearer and charge the image bearer, an exposure device to expose the image bearer and form a latent image, a developing device to develop the latent image on the image bearer into a toner image, a transfer device to transfer the toner image from the image bearer onto a transfer medium, and a cleaning blade to contact the surface of the image bearer and remove toner from the image bearer after image transfer. The charging member has surface unevenness created by projections and recesses extending in a direction of rotation of the image bearer. The cleaning blade is configured to abrade projections formed on the surface of the image bearer.

Abstract: An image forming apparatus includes an image carrier to carry a toner image, a transfer member to form a transfer nip by contacting the image carrier surface, and a power supply to output a voltage to the recording material captured in the transfer nip so as to transfer the toner image formed on the image carrier surface. The voltage is switching alternately between a voltage in the transfer direction and a voltage opposite to the voltage in the transfer direction, and a time average value (Vave) of the voltage is set to have a polarity of the transfer direction, and is set to a value in the transfer voltage side, and a change mode to change a cycle of the voltage output from the power supply can be changed based on the toner deterioration information which determines the deterioration status of the toner.

Abstract: A belt tracking system for controlling the lateral position of a movable belt entrained about a plurality of generally parallel rollers for moving in a trans-axial direction perpendicular to an axial direction in which the rollers extend parallel to each other includes a roller shaft, a slidable member, and a rotation restrictor. The roller shaft extends outward in the axial direction from an axial end of a specific one of the plurality of generally parallel rollers. The slidable member is slidably disposed around the roller shaft to move along the roller shaft as the belt moves laterally outward in the axial direction. The rotation restrictor is disposed adjacent to the slidable member to restrict rotation of the slidable member around the roller shaft.

Abstract: An image forming apparatus includes a transfer member configured to abut against an image carrier for carrying a toner image to form a transfer nip; and a power supply configured to output a bias voltage for transferring the toner image on the image carrier onto a recording medium nipped in the transfer nip. The bias voltage includes a first voltage for transferring the toner image from the image carrier onto the recording medium in a transfer direction and a second voltage having an opposite polarity of the first voltage, the first and the second voltages being alternately output. A time-averaged value of the bias voltage is set to a polarity in the transfer direction and is set in the transfer direction side with respect to a median between a maximum and a minimum of the bias voltage.

Abstract: A cleaning device disposed downstream from a transfer position in a direction of rotation of the image carrier to remove toner from the image carrier. The cleaning device includes a normally-charged toner cleaning member to electrostatically remove normally-charged toner from the image carrier, one of a polarity controller to control the toner on the image carrier to have a normal charging polarity and a reversely-charged toner cleaning member to electrostatically remove reversely-charged toner from the image carrier, a pre-cleaning member to electrostatically remove normally-charged toner from the image carrier, a pre-collection member to electrostatically collect the toner from the pre-cleaning member, and a control unit to reduce a voltage applied to the pre-cleaning member immediately after an untransferred toner image is removed from the image carrier by the pre-cleaning member below a voltage applied to the pre-cleaning member during removal of the untransferred toner image.

Abstract: There is provided a pre-cleaning brush roller being a pre-cleaning member which is disposed on an upstream of a normally-charged-toner cleaning brush roller and an oppositely-charged-toner cleaning brush roller in a surface moving direction of an intermediate transfer belt, is applied with a voltage having a polarity opposite to a normal charge polarity of toner, and electrostatically removes the toner having the normal charge polarity.

Abstract: An image forming apparatus includes a nip forming member and a transfer bias output device that outputs a transfer bias to form a transfer electric field in a transfer nip between the nip forming member and an intermediate transfer member. Upon transfer of a composite toner image including a particular toner image onto a recording medium in the transfer nip, the transfer bias output device outputs the transfer bias including a first superimposed bias in which a direct current (DC) component is superimposed on an alternating current (AC) component. Upon transfer of the composite toner image without the particular toner image onto the recording medium in the transfer nip, the transfer bias output device outputs one of the transfer bias including a second superimposed bias having a peak-to-peak value of the AC component smaller than that of the first superimposed bias and the transfer bias including only the DC component.

Abstract: According to an embodiment, provided is a transfer device including: a nip forming member that abuts against a surface of an image carrier carrying a toner image; and a transfer voltage application unit that applies a transfer voltage including a DC component and an AC component. The transfer voltage is an alternating voltage in which a supply voltage having polarity in a transfer direction and a return voltage having polarity opposite. A time average value Vave of the transfer voltage is set to be at polarity in the transfer direction and is set to be closer to a peak value Vt of the supply voltage relative to a center value Voff between a maximum and minimum value. An absolute value of the peak value Vr of the return voltage is set to be larger than an absolute value of the time average value Vave.

Abstract: A transfer device includes a rotatable image bearing member to bear a toner image on a surface thereof, a nip forming member to contact the surface of the image bearing member, and a bias output device to output a bias current to alternately form a transfer-direction electric field to transfer toner charged with a normal polarity in a toner image formed on the image bearing member to move therefrom to a recording medium and a return-direction electric field to return the toner from the recording medium to the image bearing member. A transition time T1 from a first time at which a current for forming the transfer-direction electric field reaches its maximum (It) to a second time at which a current for forming the return-direction electric field reaches its maximum (Ir) is longer than a transition time T2 from the second time to the first time.

Abstract: A cleaning apparatus including: a normally-charged toner cleaning member that receives a voltage having a polarity reverse to a normal charging polarity of a toner and electostatically removes a toner having the normal charging polarity on a cleaning target; a reversely-charged toner cleaning member that receives a voltage having the same polarity as the normal charging polarity of a toner and electrostatically removes a toner having a polarity reverse to the normal charging polarity on the cleaning target; and a pre-cleaning member that is disposed at an upstream side of the normally-charged toner cleaning member and the reverse-charged toner cleaning member in a surface moving direction of the cleaning target, receives a voltage having a polarity reverse to the normal charging polarity of the toner, and electrostatically removes a toner having the normal charging polarity on the cleaning target, is provided.