摘要:
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.
摘要:
An image forming apparatus includes an image bearer, a transfer member, and a power source. The image bearer includes a plurality of layers. The transfer member forms a transfer nip between the image bearer and the transfer member. The power source outputs a transfer bias to transfer a toner image from the image bearer onto a recording sheet in the transfer nip. The transfer bias alternates between a transfer-side bias that causes the toner image to move from the image bearer to the recording sheet, and an opposite-side bias different from the transfer-side bias. A duty ratio of a time period, during which the opposite-side bias is output, relative to one cycle of a waveform, is greater than 50%.
摘要:
A cleaner includes a cleaning member electrostatically removing toner on an object; a first electricity supplier supplying a first voltage (or current) with polarity opposite to that of toner to the cleaning member; a toner collecting member collecting toner from the cleaning member; and a second electricity supplier supplying a second voltage with the polarity greater than the first voltage to the toner collecting member. The first and second electricity suppliers set plural setting values of the first and second voltages smaller than the targeted values of the first and second voltages, and first and second control members of the first and second electricity suppliers output first and second control signals while changing in step-by-step manner so that first and second output members of the first and second electricity suppliers apply the first and second voltage in step-by-step manner before the first and second voltages reach the targeted voltages.
摘要:
The image forming apparatus includes an image bearing member bearing a toner image; a driving roller and a tension roller movable in such a direction that the interval between the rollers changes; a transfer belt stretched by the rollers to feed a receiving material so that the toner image on the image bearing member is transferred onto the receiving material or to directly receive the toner image from the image bearing member; a detector opposed to the tension roller with the belt therebetween to optically detect a mark on the belt, wherein the detector is movably supported while biased toward the tension roller, and the moving direction of the tension roller is substantially the same as an optical axis of light emitted by the detector; and a regulator to regulate movement of the tension roller and the detector in a direction perpendicular to the moving direction of the tension roller.
摘要:
An image forming apparatus includes a print head, an endless belt, a pressure roller, and a controller. The print head is configured to eject droplets of ink from multiple nozzles onto a recording sheet. The endless belt is stretched around at least first and second rollers, and is configured to convey the recording sheet placed on an outer surface thereof. The pressure roller is configured to exert pressure against the outer surface of the endless belt. The controller is configured to move the endless belt into a correcting position where the pressure roller meets a given portion of the endless belt. The given portion of the endless belt is previously retained in contact with the first roller and develops deformation due to the previous retention. The pressure exerted by the pressure roller corrects the deformation while the endless belt is in the correcting position.
摘要:
An image forming apparatus including an image formation device that forms an image on a recording medium at an image formation position; a transfer path that reverses and transfers the recording medium to the image formation position; a pair of rotation rollers that nip the recording medium in the transfer path at an upstream position relative to the position where the recording medium is completely reversed; a pull-in path provided at a downstream position relative to the pair of rotation rollers situated in the transfer path, to which the recording medium is pulled in; and a transfer control device that controls pulling in the recording medium to the pull-in path after the rear end of the recording medium passes through the pair of rotation rollers when the recording medium is fed to and transferred in the transfer path, wherein no pair of rollers that impart a transfer force to the recording medium are provided in the pull-in range of the recording medium in the pull-in path.
摘要:
An image forming apparatus includes a rotatable image bearer, a transfer rotator, a detector, and circuitry. The image bearer bears an image. The transfer rotator transfers the image from the image bearer onto a recording medium sandwiched and conveyed between the image bearer and the transfer rotator. The detector detects length information indicating a length, in a direction of conveyance of the recording medium, of the image on the recording medium. The circuitry corrects a correction value, based on the length information detected by the detector and a target value of the length information, to correct an image magnification, in the direction of conveyance of the recording medium, of the image to be formed on the recording medium. The circuitry controls an image forming operation of forming the image on the recording medium with the correction value.
摘要:
A belt running device includes a plurality of rollers, a belt, a guide, a regulating member, and an abutting member. The belt is wound around the plurality of rollers and configured to rotate. The guide is provided at an end of an inner peripheral surface of the belt. The regulating member is provided at an end of at least one roller of the plurality of rollers in the axial direction of the at least one roller and configured to contact the guide and regulate a movement of the belt in the axial direction of the at least one roller. The abutting member is configured to contact an outer peripheral surface of the belt to press the belt inward in a vicinity of a contact start point at which the guide and the regulating member start to contact when the belt runs.
摘要:
A belt device includes a belt unit including a plurality of rotators and a belt looped around the plurality of rotators. The belt device further includes a frame including a plurality of support portions to support the belt unit, a biasing member to bias the belt unit supported by the frame in a predetermined direction, and an adjuster to adjust a position of at least one of the plurality of support portions.
摘要:
An image forming apparatus includes an image bearer; a toner image forming device; an intermediate transferor; a primary transfer power source; a secondary transfer nip forming device; and a secondary transfer power source to output a secondary transfer bias. One of two peak values of the secondary transfer bias is a transfer peak value to provide a greater transfer-directional force to move toner from the intermediate transferor toward the recording medium in the secondary transfer nip. An absolute value of the transfer peak value is greater than an absolute value of the primary transfer bias.