Abstract: An image forming apparatus includes a plurality of image carriers that carries toner images, a belt that is supported by a plurality of rollers including a support roller and an opposing roller, a transfer roller disposed opposed to the opposing roller via the belt, and a bending roller that bends the belt from outside toward inside and is disposed downstream from the opposing roller and upstream from support roller. The belt is stretched between the support roller and the bending roller in a first area. The plurality of image carriers contacts the belt in a second area other than the first area. A surface of the belt in the first area is parallel to that of the belt in the second area.

Abstract: The image forming apparatus includes a process unit, a latent image writer, a power source, and a controller. The process unit is detachably attachable relative to the image forming apparatus and includes, as a single integrated unit, a latent image bearing member to bear a latent image on a surface thereof, a charging device to charge the surface of the latent image bearing member, and a development device to develop the latent image with toner. The controller causes the power source to output a charging bias at a predetermined target level supplied to the charging device. The process unit includes a first storage device to store correction information for calculating the predetermined target level of the charging bias in accordance with a combination of the latent image bearing member and the charging device. The controller corrects the predetermined target level based on the correction information in the first storage device.

Abstract: The image forming apparatus includes a process unit, a latent image writer, a power source, and a controller. The process unit is detachably attachable relative to the image forming apparatus and includes, as a single integrated unit, a latent image bearing member to bear a latent image on a surface thereof, a charging device to charge the surface of the latent image bearing member, and a development device to develop the latent image with toner. The controller causes the power source to output a charging bias at a predetermined target level supplied to the charging device. The process unit includes a first storage device to store correction information for calculating the predetermined target level of the charging bias in accordance with a combination of the latent image bearing member and the charging device. The controller corrects the predetermined target level based on the correction information in the first storage device.

Abstract: An image forming apparatus includes a plurality of image carriers that carries toner images, a belt that is supported by a plurality of rollers including a support roller and an opposing roller, a transfer roller disposed opposed to the opposing roller via the belt, and a bending roller that bends the belt from outside toward inside and is disposed downstream from the opposing roller and upstream from support roller. The belt is stretched between the support roller and the bending roller in a first area. The plurality of image carriers contacts the belt in a second area other than the first area. A surface of the belt in the first area is parallel to that of the belt in the second area.

Abstract: A transfer unit includes a belt member, a bending roller, a transfer section, and a bias application unit. The belt member is extended between rollers and has a movable surface on which a toner image is transferred from an image carrier. The bending roller externally contacts the surface of the belt member to bend the belt member and rotates in conjunction with the belt member. The transfer section includes one of the rollers and a surface moving member. The surface moving member rotates at least one full turn while cleaning is performed on the surface moving member and the bending roller. A surface moving speed of the bending roller is equal to or greater than a surface moving speed of the surface moving member. A circumferential length L1 of the surface moving member and a circumferential length L2 of the bending roller satisfy L1?L2.

Abstract: An image forming apparatus includes a toner image carrying member, an image transfer device, a fixing device, a registration unit, a guide member, an upstream-side transportation unit, and a downstream-side transportation unit. The image transfer device transfers a toner image from the toner image carrying member to a recording medium. The fixing device fixes the toner image. The registration unit transports the recording medium. The guide member guides the recording medium. The upstream-side transportation unit includes an upstream-side transportation member, disposed at an upstream side in the transport direction of the recording medium. The downstream-side transportation unit includes the downstream-side transportation member, disposed at a downstream side in the transport direction of the recording medium. The upstream-side transportation unit includes an upstream-side positioning member to position the guide member to the upstream-side transportation member.

Abstract: An image forming apparatus in which a visible image is transferred to a transfer material includes a pre-transfer exposing unit that makes only a portion of a latent image carrier that corresponds to a leading edge of the transfer material expose, and a transfer-bias applying unit that applies a bias for transferring the visible image. The transfer-bias applying unit starts applying the bias to the transfer material, at least step-by-step, when a predetermined time is passed from a point of time at which the leading edge of the transfer material comes into a contact with the latent image carrier by controlling the pre-transfer exposing unit and a bias applying timing of the transfer-bias applying unit.

Abstract: An image forming apparatus includes a toner image carrying member, an image transfer device, a fixing device, a registration unit, a guide member, an upstream-side transportation unit, and a downstream-side transportation unit. The image transfer device transfers a toner image from the toner image carrying member to a recording medium. The fixing device fixes the toner image. The registration unit transports the recording medium. The guide member guides the recording medium. The upstream-side transportation unit includes an upstream-side transportation member, disposed at an upstream side in the transport direction of the recording medium. The downstream-side transportation unit includes the downstream-side transportation member, disposed at a downstream side in the transport direction of the recording medium. The upstream-side transportation unit includes an upstream-side positioning member to position the guide member to the upstream-side transportation member.

Abstract: A transfer unit includes a belt member, a bending roller, a transfer section, and a bias application unit. The belt member is extended between rollers and has a movable surface on which a toner image is transferred from an image carrier. The bending roller externally contacts the surface of the belt member to bend the belt member and rotates in conjunction with the belt member. The transfer section includes one of the rollers and a surface moving member. The surface moving member rotates at least one full turn while cleaning is performed on the surface moving member and the bending roller. A surface moving speed of the bending roller is equal to or greater than a surface moving speed of the surface moving member. A circumferential length L1 of the surface moving member and a circumferential length L2 of the bending roller satisfy L1?L2.

Abstract: An image forming apparatus in which a visible image is transferred to a transfer material includes a pre-transfer exposing unit that makes only a portion of a latent image carrier that corresponds to a leading edge of the transfer material expose, and a transfer-bias applying unit that applies a bias for transferring the visible image. The transfer-bias applying unit starts applying the bias to the transfer material, at least step-by-step, when a predetermined time is passed from a point of time at which the leading edge of the transfer material comes into a contact with the latent image carrier by controlling the pre-transfer exposing unit and a bias applying timing of the transfer-bias applying unit.

Abstract: An image forming apparatus in which a visible image is transferred to a transfer material includes a pre-transfer exposing unit that makes only a portion of a latent image carrier that corresponds to a leading edge of the transfer material expose, and a transfer-bias applying unit that applies a bias for transferring the visible image. The transfer-bias applying unit starts applying the bias to the transfer material, at least step-by-step, when a predetermined time is passed from a point of time at which the leading edge of the transfer material comes into a contact with the latent image carrier by controlling the pre-transfer exposing unit and a bias applying timing of the transfer-bias applying unit.

Abstract: An image forming apparatus in which a visible image is transferred to a transfer material includes a pre-transfer exposing unit that makes only a portion of a latent image carrier that corresponds to a leading edge of the transfer material expose, and a transfer-bias applying unit that applies a bias for transferring the visible image. The transfer-bias applying unit starts applying the bias to the transfer material, at least step-by-step, when a predetermined time is passed from a point of time at which the leading edge of the transfer material comes into a contact with the latent image carrier by controlling the pre-transfer exposing unit and a bias applying timing of the transfer-bias applying unit.

Abstract: An image transferring and recording medium conveying device, for an image forming apparatus, which includes a nip between a belt and an image carrier for image transfer to a recording medium. A bias applying device applies a bias for image transfer to the nip. An image transfer bias Tb is applied during a leading edge interval, in which the leading edge portion of the recording medium between the leading edge and a preselected position in the direction of medium conveyance moves away from the nip. An image transfer bias Ta is applied to the nip during a remaining interval, in which the remaining portion of the recording medium moves away from the nip. A controller switches the image transfer bias Tb within a range lower than the image transfer bias Ta and greater than an image transfer bias Tc.

Abstract: An image transferring and recording medium conveying device for an image forming apparatus of the present invention includes a belt forming a nip for image transfer between it and an image carrier and conveying a recording medium via the nip to thereby transfer a toner image formed on the image carrier to the recording medium. A bias applying device applies a bias for image transfer to the nip. Assume that an image transfer bias Tb is applied during a leading edge interval in which the leading edge portion of the recording medium between the leading edge and a preselected position in the direction of medium conveyance moves away from the nip, and that an image transfer bias Ta is applied to the nip during a remaining interval in which the remaining portion of the recording medium moves away from the nip. Then, a controller switches the image transfer bias Tb within a range lower than the image transfer bias Ta.