Abstract: An image forming apparatus includes a belt-shaped image bearer; a transfer device disposed opposing to the image bearer; an opposed device disposed opposing to the transfer device; and a transfer bias power source. The image bearer is disposed along an outer circumferential surface of the transfer device at at least one of an upstream side and a downstream side of the transfer portion in a direction of conveyance of the recording medium. The transfer bias power source cyclically alternates the transfer bias applied to the transfer portion, between a transfer directional bias in a transfer direction to transfer the toner image from the image bearer onto the recording medium and a reverse directional bias in a reverse direction of the transfer direction. The transfer bias power source applies the reverse directional bias during a time period longer than 50% of one cycle of the applied transfer bias in the one cycle.

Abstract: A transfer device includes a transfer member and a bias applicator. The transfer member contacts a surface, on which a toner image is borne, of an image bearing body, to form a transfer nip. The bias applicator applies a DC voltage and an AC voltage as transfer bias to transfer the toner image on the image bearing body to a recording sheet in the transfer nip. The bias applicator applies a DC voltage having a same polarity as the DC voltage of the transfer bias and an AC voltage having an amplitude smaller than the AC voltage of the transfer bias or applies the DC voltage having the same polarity as the DC voltage of the transfer bias without applying an AC voltage, when an inter-sheet area that exists on the image bearing body passes through the transfer nip during a continuous image formation period.

Abstract: An image forming apparatus includes an image carrier, a transfer member, a power supply, and a control device that controls the power supply to output a DC-AC superimposed bias or a DC bias to transfer a toner image on the image carrier onto a recording medium. The control device controls the power supply to alternately output a first bias being a DC component the same in polarity as the DC bias and a second bias being a DC component opposite in polarity to the DC bias to clean the transfer member when image formation is not taking place. The first bias is output with two target output values including a first value and a second value lower than the first value. The second bias is output with one target output value. An output time of the second bias is longer than an output time of the first bias.

Abstract: An image forming apparatus includes a rotatable image bearing member, a nip forming member, and a power source. The rotatable image bearing member bears a toner image on a surface thereof and rotates. The nip forming member contacts the surface of the image bearing member to form a transfer nip therebetween. The power source applies a transfer bias to the transfer nip to transfer the toner image from the image bearing member onto a recording medium interposed in the transfer nip. The transfer bias includes a superimposed transfer bias in which an alternating current (AC) component is superimposed on a direct current (DC) component and a polarity of the superimposed transfer bias changes with time. A phase difference between an AC voltage and an AC current output from the power source is equal to or less than 0.47 cycles.

Abstract: An image forming apparatus includes a toner forced consumption control unit that performs toner forced consumption control in which toner in a developing unit is forcibly consumed when a certain condition to perform the toner forced consumption control is met. The certain condition to perform the toner forced consumption control includes a specific performance condition that a transfer bias switching condition to switch a transfer bias to a superimposed transfer bias in which an alternating current component is superimposed on a direct current component, from a direct current transfer bias is met. When the specific performance condition is met, the toner forced consumption control unit performs preliminary toner forced consumption control in which the toner forced consumption control is performed before an image forming operation using the superimposed transfer bias is started.

Abstract: An image forming apparatus includes an image carrier that carries a toner image; a transfer member that forms a transfer nip between the transfer member and the image carrier; and a power supply capable of outputting a superimposed transfer bias in which an alternating current component is superimposed onto a direct current component. The toner image on the image carrier is transferred onto a recording medium in the transfer nip by the superimposed transfer bias or a direct current bias consisting of the direct current component output by the power supply. The apparatus also includes a controller that controls the power supply so that an output target value of the direct current component when the direct current component rises up is larger than an output target value of the direct current component when the toner image is transferred onto the recording medium.

Abstract: An image forming apparatus includes an image carrier, a transfer member, a power supply, and a control device that controls the power supply to output a DC-AC superimposed bias or a DC bias to transfer a toner image on the image carrier onto a recording medium. The control device controls the power supply to alternately output a first bias being a DC component the same in polarity as the DC bias and a second bias being a DC component opposite in polarity to the DC bias to clean the transfer member when image formation is not taking place. The first bias is output with two target output values including a first value and a second value lower than the first value. The second bias is output with one target output value. An output time of the second bias is longer than an output time of the first bias.

Abstract: A transfer device includes a transfer member and a bias applicator. The transfer member contacts a surface, on which a toner image is borne, of an image bearing body, to form a transfer nip. The bias applicator applies a DC voltage and an AC voltage as transfer bias to transfer the toner image on the image bearing body to a recording sheet in the transfer nip. The bias applicator applies a DC voltage having a same polarity as the DC voltage of the transfer bias and an AC voltage having an amplitude smaller than the AC voltage of the transfer bias or applies the DC voltage having the same polarity as the DC voltage of the transfer bias without applying an AC voltage, when an inter-sheet area that exists on the image bearing body passes through the transfer nip during a continuous image formation period.

Abstract: An image forming apparatus includes a rotatable image bearing member, a nip forming member, and a power source. The rotatable image bearing member bears a toner image on a surface thereof and rotates. The nip forming member contacts the surface of the image bearing member to form a transfer nip therebetween. The power source applies a transfer bias to the transfer nip to transfer the toner image from the image bearing member onto a recording medium interposed in the transfer nip. The transfer bias includes a superimposed transfer bias in which an alternating current (AC) component is superimposed on a direct current (DC) component and a polarity of the superimposed transfer bias changes with time. A phase difference between an AC voltage and an AC current output from the power source is equal to or less than 0.47 cycles.

Abstract: An image forming apparatus includes a toner forced consumption control unit that performs toner forced consumption control in which toner in a developing unit is forcibly consumed when a certain condition to perform the toner forced consumption control is met. The certain condition to perform the toner forced consumption control includes a specific performance condition that a transfer bias switching condition to switch a transfer bias to a superimposed transfer bias in which an alternating current component is superimposed on a direct current component, from a direct current transfer bias is met. When the specific performance condition is met, the toner forced consumption control unit performs preliminary toner forced consumption control in which the toner forced consumption control is performed before an image forming operation using the superimposed transfer bias is started.

Abstract: An image forming apparatus is provided, which forms a releasing agent absorption toner image on an in-between printed sides area of a moving surface of an image carrier in the duplex printing mode. When the in-between printed sides area of the moving surface enters a transfer position at which a toner image is transferred from the image carrier to a recording medium, the transferring operation of transferring the toner image from the image carrier to a recording medium is interrupted to keep the releasing agent absorption toner image on the in-between printed sides area of the moving surface of the image carrier.

Abstract: A developing unit, which is incorporated in an image forming apparatus, includes a developer case to accommodate a two-component developer including toner and carrier, a developer bearing member bearing the two-component developer to supply the developer to an image, a developer supply path formed inside the developer case to supply the developer along the developer bearing member, an agitation and conveyance member disposed in the developer supply path, a toner collecting mechanism to collect toner after development, and a collected toner conveyance path formed inside the developer case and including a collected toner conveying member. The collected toner conveyance path and the developer supply path are arranged in communication with each other in the vicinity of one end portion of the collected toner conveyance path in a direction of conveyance of collected toner so as to circulate toner unused for development.

Abstract: An image forming apparatus includes multiple image forming units disposed adjacent to and horizontally aligned with each other to form respective single non-black color images, a first transfer member to sequentially transfer and overlay the respective single non-black color images thereon for forming a composite color image, a black image forming unit disposed separately from the multiple image forming units including a black image carrier and a black image developing unit, a second transfer member to transfer the black image from the black image forming unit onto a recording medium, a first cleaning unit to clean the surface of the black image carrier, and a second cleaning unit to clean the surface of the second transfer member. The black toner removed from the surface of the black image carrier is collected to the black image developing unit.

Abstract: An image forming apparatus includes a transfer device, a voltage applicator, a current sensor, and a discharge detector. The transfer device transfers a toner image from one surface to another by developing an electrical field across a transfer gap when provided with a transfer bias. The voltage applicator applies a stepped test voltage to the transfer device. The current sensor senses a current flowing to the transfer device during application of the test voltage the discharge detector detects an electrical discharge occurring in the transfer gap based on a rate of increase of the sensed current.

Abstract: A sheet cutter cuts an adhesion sheet and includes a pair of blades including a first blade including a blade edge and a second blade opposing the first blade and including a blade edge. The pair of blades cuts a border of the adhesion sheet. The adhesion sheet is formed by adhering a first sheet, at least a part of which is transparent and bears a mirror image, to a non-transparent second sheet including an adhesive layer, to oppose the mirror image on the first sheet against the adhesive layer of the second sheet.

Abstract: A control unit controls a device that executes an image forming process, compares changes of each toner adhesion amount in an image-density-detection pattern image when a developing-bias control condition is changed, with respect to a toner adhesion amount in an image-density-detection pattern image in a normal status, performs a malfunction-occurrence prediction process according to the degree of each change of the densities, and displays the result.

Abstract: A sheet laminator includes a bonding unit and a restricting unit. The bonding unit bonds a first sheet to a second sheet that includes an adhesive layer. The restricting unit restricts movement of any one of the first sheet and the second sheet thereby preventing bonding between the first sheet and the second sheet before the first sheet and the second sheet reach the bonding unit.

Abstract: An image forming apparatus includes an image carrier configured to carry an image on a surface thereof, a cleaning unit including a cleaning blade and configured to remove residual toner remaining on the surface of the image carrier with the cleaning blade, and an application unit including a brush roller having a modified cross-section fiber and configured to use the brush roller to scrape molded lubricant into scraped lubricant and apply the scraped lubricant to the image carrier. A process cartridge is provided to the image forming apparatus and integrally includes the image carrier, the cleaning unit, the application unit, and at least one of a charging unit and a developing unit in a single unit.

Abstract: An image forming apparatus includes multiple image forming units disposed adjacent to and horizontally aligned with each other to form respective single non-black color images, a first transfer member to sequentially transfer and overlay the respective single non-black color images thereon for forming a composite color image, a black image forming unit disposed separately from the multiple image forming units including a black image carrier and a black image developing unit, a second transfer member to transfer the black image from the black image forming unit onto a recording medium, a first cleaning unit to clean the surface of the black image carrier, and a second cleaning unit to clean the surface of the second transfer member. The black toner removed from the surface of the black image carrier is collected to the black image developing unit.

Abstract: A developing unit, which is incorporated in an image forming apparatus, includes a developer case to accommodate a two-component developer including toner and carrier, a developer bearing member bearing the two-component developer to supply the developer to an image, a developer supply path formed inside the developer case to supply the developer along the developer bearing member, an agitation and conveyance member disposed in the developer supply path, a toner collecting mechanism to collect toner after development, and a collected toner conveyance path formed inside the developer case and including a collected toner conveying member. The collected toner conveyance path and the developer supply path are arranged in communication with each other in the vicinity of one end portion of the collected toner conveyance path in a direction of conveyance of collected toner so as to circulate toner unused for development.