An image forming apparatus includes a body, a conveyance unit, an image carrier, a transfer unit, and a pre-transfer guide. The body has a sheet passage for conveying sheets along inner and outer conveyance surfaces mutually facing. The conveyance unit includes the outer conveyance surface and is supported pivotably between an open position and a closed position relative to the inner conveyance surface. The transfer unit rotatably supports a transfer roller. The pre-transfer guide includes a first guide on the outer conveyance surface and a second guide on the inner conveyance surface. The first guide has a contact segment protruding toward the second guide. The first guide and the transfer unit are supported independently swingably relative to the transfer unit. The first guide is urged toward the second, and the distance between the two guide surfaces is restricted by the contact segment touching a contacted portion.

A control unit performs control to make a direction of an electric field generated in a first area of an image carrier forming a transfer portion during image forming operation, relative to a voltage applied to a brush member in a state where the first area passes through a contact portion, different from a direction of an electric field generated in a second area of the image carrier forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the image carrier is rotated at a first speed to second operation in which the image carrier is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation.

An image forming apparatus includes: a circulating member that is a part of a transport path that transports a recording medium; a holding member that is fixed to the circulating member, circulates, and holds a leading end portion of the recording medium; an image forming section that forms an image on the recording medium at an image forming position in a circulation path of the circulating member; and a feeding section that feeds out the recording medium to a holding position where the holding member holds the leading end portion of the recording medium. When a circulation velocity Vg is defined as a velocity at which the circulating member circulates the holding member, a transport velocity of the recording medium is reduced from a first transport velocity V1, which is higher than the circulation velocity Vg, to a second transport velocity V2, which is lower than the first transport velocity V1, before the leading end portion of the recording medium enters the holding position.

An image forming apparatus includes a fixing device, control circuitry, and a controller. The fixing device includes a first rotating body, a second rotating body in pressure contact with the first rotating body, and a heat source to heat the first rotating body. The circuitry, at startup of the fixing device, causes the fixing device to perform a rotating operation to rotate the first rotating body while causing the heat source to perform a heating operation to heat the first rotating body, thereby performing a fixing startup operation to raise a temperature of the first rotating body. The circuitry delays at least one of a timing for start of the rotating operation and a timing for start of the heating operation to be later than a start of a controller startup operation such that the fixing startup operation is completed in time with completion of the controller startup operation.

An image forming apparatus includes an image bearer; a nip forming member configured to form a transfer nip between the image bearer and the nip forming member; a nip pressure changer configured to change a nip pressure of the transfer nip; a transfer bias applier configured to apply, to the transfer nip, a transfer bias in which an AC component is superimposed on a DC component; and a DC component adjuster configured to adjust the DC component in the transfer bias, according to the nip pressure that is changed by the nip pressure changer.

A fixing device includes a first rotating body, a second rotating body, a frame, a shutter, a pressure arm, a cam, a shutter arm, and an arm cam. The shutter is rotatable about a first axis between a closed position and an open position. The pressure arm presses the first rotating body against the second rotating body. The cam is rotatable about a second axis and pushes the pressure arm. The shutter arm is connected to the shutter and rotates about the second axis independent of the cam, to cause the shutter to rotate between the closed position and the open position. The arm cam rotates about the second axis to push the shutter arm at a position offset from the second axis and cause the shutter arm to rotate about the second axis.

An image forming apparatus includes a photosensitive drum and an apparatus main body, the apparatus main body includes a transfer roller exerting a transfer pressing force on the photosensitive drum, a positioning portion positioning the photosensitive drum in first and second directions by being contacted by a bearing portion holding a rotation axis of the photosensitive drum, the first direction being in a virtual plane perpendicular to the rotation axis, and the second direction being a direction intersecting the first direction, and a pressing member exerting a holding-and-pressing force pressing the bearing portion toward the positioning portion, and, in a state in which the bearing portion is in contact with the positioning portion, the holding-and-pressing force has a component force in the first direction, and the transfer pressing force has a component force in the second direction that is oriented to press the bearing portion toward the positioning portion.

A jacket includes: a first layer that is on a cylinder body side when the jacket is attached to a rotating cylinder body; and a second layer that is a layer located on a side opposite to the cylinder body with respect to the first layer, has a hardness lower than that of the first layer, and does not exist at a position where at least one of end edges of the cylinder body in a rotation axis direction is located inward of the first layer in the rotation axis direction.

A transfer device includes: a transfer drum that has a groove-like recess extending in an axial direction in an outer circumferential portion thereof, rotates about an axis thereof, and comes into contact with a medium being transported at a portion thereof on an upstream side of the recess in a rotation direction; a nip member, the nip member and the transfer drum forming therebetween a nip part where the medium is nipped; an application member that applies a voltage to the nip part where the medium is nipped, so that an image is transferred to the medium; and a contact mechanism that causes the nip member to come into contact only with a portion on the upstream side of the recess in the transfer drum in the rotation direction at a transfer-start time when the transfer of the image to the medium starts.

An image forming apparatus comprising includes an image carrying member including a movable surface to include a toner image; a transfer roller to form a transfer nip between the transfer roller and the movable surface of the image carrying member, to move position in a direction in correspondence to a thickness of a print medium to intersect a direction of introduction of the print medium into the transfer nip, and to receive a transfer bias voltage to transfer the toner image from the movable surface of the image carrying member to the print medium; and a movement guide structure to guide the print medium toward the transfer nip, and to move in synchronization with the movement of the position of the transfer roller to change a gap between an end of the movement guide structure facing the image carrying member and the image carrying member.