Abstract: There is provided a head bar unit including a head bar, an adjuster and a movement. The head bar includes a plurality of heads. The adjuster is supported by the head bar, and is configured to adjust positions in a vertical direction of the heads. The movement is configured to move the head bar and the adjuster in the vertical direction. The adjuster includes a motor, a rotator and a stopper. The rotator includes a plurality of contact portions. The rotator is configured to be rotated by the motor around a rotating shaft. The stopper is located at a position facing the rotator in the vertical direction, and is configured to position the rotator in the vertical direction, by making contact with one of the contact portions.

Abstract: There is provided a head bar unit including a head bar, an adjuster and a movement. The head bar includes a plurality of heads. The adjuster is supported by the head bar, and is configured to adjust positions in a vertical direction of the heads. The movement is configured to move the head bar and the adjuster in the vertical direction. The adjuster includes a motor, a rotator and a stopper. The rotator includes a plurality of contact portions. The rotator is configured to be rotated by the motor around a rotating shaft. The stopper is located at a position facing the rotator in the vertical direction, and is configured to position the rotator in the vertical direction, by making contact with one of the contact portions.

Abstract: An image forming apparatus, including: a sheet cassette; an image former; a fixer; a discharge tray; a conveyor configured to convey a sheet along a conveyance passage; a return conveyor configured to convey the sheet from a branch position between the fixer and the discharge tray to a merge position between the sheet cassette and the image former along a return passage which is branched from the conveyance passage at the branch position, passes below the sheet cassette, and merges with the conveyance passage at the merge position; a switchback roller disposed between the branch position and the discharge tray in the conveyance passage and configured to convey the sheet to the discharge tray when it rotates forwardly and to the return passage when it rotates backwardly; and an intermediate conveyance roller disposed in the return passage at a height level intermediate between the fixer and the sheet cassette.

Abstract: An image forming apparatus configured to form images on a first surface and a second surface of a sheet includes an apparatus body, an image forming unit, a feed tray, and a return unit configured to return the sheet having an image formed on the first surface of the sheet toward the image forming unit. The return unit includes a first guide, a second guide, and an adjuster. The first guide is detachably attached to the second guide and includes a first roller and a positioned portion. The second guide is positioned in the apparatus body and includes a second roller facing the first roller, and a positioning portion configured to contact the positioned portion of the first guide, thereby positioning the first guide relative to the second guide. The adjuster is configured to adjust an orientation of the second guide relative to the apparatus body.

Abstract: An image forming apparatus, including: a sheet cassette; an image former; a fixer; a discharge tray; a conveyor configured to convey a sheet along a conveyance passage; a return conveyor configured to convey the sheet from a branch position between the fixer and the discharge tray to a merge position between the sheet cassette and the image former along a return passage which is branched from the conveyance passage at the branch position, passes below the sheet cassette, and merges with the conveyance passage at the merge position; a switchback roller disposed between the branch position and the discharge tray in the conveyance passage and configured to convey the sheet to the discharge tray when it rotates forwardly and to the return passage when it rotates backwardly; and an intermediate conveyance roller disposed in the return passage at a height level intermediate between the fixer and the sheet cassette.

Abstract: An image forming apparatus configured to form images on a first surface and a second surface of a sheet includes an apparatus body, an image forming unit, a feed tray, and a return unit configured to return the sheet having an image formed on the first surface of the sheet toward the image forming unit. The return unit includes a first guide, a second guide, and an adjuster. The first guide is detachably attached to the second guide and includes a first roller and a positioned portion. The second guide is positioned in the apparatus body and includes a second roller facing the first roller, and a positioning portion configured to contact the positioned portion of the first guide, thereby positioning the first guide relative to the second guide. The adjuster is configured to adjust an orientation of the second guide relative to the apparatus body.

Abstract: An image forming apparatus including a movement mechanism includes a first arm assembly including a first arm configured to pivot about a first pivot axis between a retracted position and a protruding position, the first arm being biased toward the protruding position and extending away from the first pivot axis in a first direction and a second arm configured to rotate between a restriction position in which the second arm engages the first arm, and a releasing position in which the second arm is separated from the first arm, the second arm configured to rotate from the restriction position to the releasing position in a direction away from the first arm, and a guide including a guide surface extending in the first direction, the guide surface configured to contact the first arm situated in the protruding position and a protruding guide configured to contact and move the second arm.

Abstract: A sheet storage device, including a storage tray configured to store a sheet therein; a board, on which the sheet to be stored in the storage tray is placed, the board being configured to be swingably supported by the storage tray at a first position closer to a first end thereof than a second end being opposite from the first end to swing about a swing axis; and a projection configured to protrude from a bottom of the storage tray toward the board, the projection including a contact part being configured to contact the board member at a second position closer to the second end than to the first end of the board, is provided. A length of the contact part along an axial direction of the swing axis is smaller than a length of the board at the second position closer to the second end.

Abstract: A sheet stackable device including a sheet stackable bin and a first edge guide is provided. The first edge guide is slidable in a first direction. The sheet stackable bin includes a first rail to guide the first edge guide, a second rails to guide the first edge guide, and teeth arranged along the first direction. The first edge guide includes a first protrusion configured to contact the first rail along a second direction orthogonal to the first direction, a second protrusion configured to contact the second rail, a locking part engageable with the teeth, and a handle to disengage the locking part from the teeth. The handle is arranged in a position between the first rail and the second rail with regard to the second direction.

Abstract: An image forming apparatus including a movement mechanism includes a first arm assembly including a first arm configured to pivot about a first pivot axis between a retracted position and a protruding position, the first arm being biased toward the protruding position and extending away from the first pivot axis in a first direction and a second arm configured to rotate between a restriction position in which the second arm engages the first arm, and a releasing position in which the second arm is separated from the first arm, the second arm configured to rotate from the restriction position to the releasing position in a direction away from the first arm, and a guide including a guide surface extending in the first direction, the guide surface configured to contact the first arm situated in the protruding position and a protruding guide configured to contact and move the second arm.

Abstract: In an image forming apparatus, an error detection mark is formed by using an image forming unit on the surface of a carrier along a detection line passing through an exposure position in a carrier moving direction. The error detection mark includes a first mark and a second mark spaced from each other by a fixed distance in the carrier moving direction. The error detection mark is measured by the sensor. A measurement error of the sensor for a registration mark is determined based on the measured values for the first mark and second mark. A registration mark is formed by using the image forming unit on the surface of the carrier on the detection line. The registration mark is measured using the sensor. Offset of an image-forming position is corrected based on the determined measurement error and a measured value for the registration mark.

Abstract: In an image forming apparatus, an image forming device have an operating part and is configured to form an image at an image formation position on an imaging target. A control device is configured to control the image forming device to start performing an image forming process, determine an adjustment amount regarding the image formation position based on an operation amount of the operating part measured during a period of time from a first specified timing in a previous image forming process to a second specified timing in or before a current image forming process, and adjust, based on the adjustment amount, the image formation position where an image is formed pursuant to the current image forming process.

Abstract: In an image forming device, a processor acquires a reference value set for the color combination of two different colors; determines whether the reference value meets an execution condition for correcting misregistration between the two different colors in two image pieces to be superposed one on the other, the determination being performed before forming a finished image including at least a color image portion formed by superposing one of the color image pieces on at least one of remaining color image pieces by using a plurality of image-forming units; forms registration marks for the two different colors in response to determination that the reference value meets the execution condition; and adjusts image-forming positions corresponding to the two different colors subject to correction of misregistration based on outputs of an light-receiving element providing detection results of the position of each of the registration marks.

Abstract: A sheet stackable device including a sheet stackable bin and a first edge guide is provided. The first edge guide is slidable in a first direction. The sheet stackable bin includes a first rail to guide the first edge guide, a second rails to guide the first edge guide, and teeth arranged along the first direction. The first edge guide includes a first protrusion configured to contact the first rail along a second direction orthogonal to the first direction, a second protrusion configured to contact the second rail, a locking part engageable with the teeth, and a handle to disengage the locking part from the teeth. The handle is arranged in a position between the first rail and the second rail with regard to the second direction.

Abstract: A sheet storage device, including a storage tray configured to store a sheet therein; a board, on which the sheet to be stored in the storage tray is placed, the board being configured to be swingably supported by the storage tray at a first position closer to a first end thereof than a second end being opposite from the first end to swing about a swing axis; and a projection configured to protrude from a bottom of the storage tray toward the board, the projection including a contact part being configured to contact the board member at a second position closer to the second end than to the first end of the board, is provided. A length of the contact part along an axial direction of the swing axis is smaller than a length of the board at the second position closer to the second end.

Abstract: In an image forming device, a processor acquires a reference value set for the color combination of two different colors; determines whether the reference value meets an execution condition for correcting misregistration between the two different colors in two image pieces to be superposed one on the other, the determination being performed before forming a finished image including at least a color image portion formed by superposing one of the color image pieces on at least one of remaining color image pieces by using a plurality of image-forming units; forms registration marks for the two different colors in response to determination that the reference value meets the execution condition; and adjusts image-forming positions corresponding to the two different colors subject to correction of misregistration based on outputs of an light-receiving element providing detection results of the position of each of the registration marks.

Abstract: There is provided an image forming apparatus, including: an image forming unit; a sheet detector positioned on a sheet conveyance path at an upstream side of the image forming unit; a conveyance belt; an image detector; and a controller. The controller is configured to perform: detecting a front end of the sheet; forming a mark image to extend over the conveyance belt and the sheet; detecting the mark image; measuring a mark conveyance time; obtaining a time elapsed based on the mark conveyance time; and forming the image when the obtained time passes from the front end of the sheet is detected.

Abstract: There is provided an image forming apparatus, including: an image forming unit; a sheet detector positioned on a sheet conveyance path at an upstream side of the image forming unit; a conveyance belt; an image detector; and a controller. The controller is configured to perform: detecting a front end of the sheet; forming a mark image to extend over the conveyance belt and the sheet; detecting the mark image; measuring a mark conveyance time; obtaining a time elapsed based on the mark conveyance time; and forming the image when the obtained time passes from the front end of the sheet is detected.

Abstract: In an image forming apparatus, an image forming device have an operating part and is configured to form an image at an image formation position on an imaging target. A control device is configured to control the image forming device to start performing an image forming process, determine an adjustment amount regarding the image formation position based on an operation amount of the operating part measured during a period of time from a first specified timing in a previous image forming process to a second specified timing in or before a current image forming process, and adjust, based on the adjustment amount, the image formation position where an image is formed pursuant to the current image forming process.

Abstract: In an image forming apparatus, an error detection mark is formed by using an image forming unit on the surface of a carrier along a detection line passing through an exposure position in a carrier moving direction. The error detection mark includes a first mark and a second mark spaced from each other by a fixed distance in the carrier moving direction. The error detection mark is measured by the sensor. A measurement error of the sensor for a registration mark is determined based on the measured values for the first mark and second mark. A registration mark is formed by using the image forming unit on the surface of the carrier on the detection line. The registration mark is measured using the sensor. Offset of an image-forming position is corrected based on the determined measurement error and a measured value for the registration mark.