Abstract: An image forming apparatus includes a belt unit and a detector unit including a detector that is disposed opposite a tension roller via a belt and a detector support that supports the detector. The detector support includes a first lateral end portion that is disposed at one lateral end of the detector support in an axial direction of the tension roller and is movably attached to an apparatus body. The detector support further includes a second lateral end portion that is disposed at another lateral end of the detector support in the axial direction of the tension roller and is attached to the apparatus body. The first lateral end portion includes an engaging groove that engages a shaft of the tension roller. The engaging groove has a mouth that is disposed at a downstream end of the engaging groove in a detaching direction of the belt unit.

Abstract: A unit accommodation apparatus includes a first unit and a second unit that are to be installed into and removed from an apparatus body through an opening in an installation-removal direction and are held by a unit holder. The unit holder includes a first positioner that is disposed opposite one lateral end of the first unit and the second unit and is detachably attached to the first unit and the second unit. A second positioner is disposed opposite another lateral end of the first unit and the second unit and holds the first unit and the second unit in a state in which the first unit and the second unit are detachably attached to the second positioner. The first positioner and the second positioner secure a relative position of the first unit relative to the second unit in a direction parallel to a hypothetical orthogonal plane perpendicular to the installation-removal direction.

Abstract: An image forming apparatus includes a photoconductor that bears an image and an intermediate transfer device that forms a primary transfer nip between the photoconductor and the intermediate transfer device. The intermediate transfer device primarily transfers the image from the photoconductor onto the intermediate transfer device at the primary transfer nip. A secondary transfer device forms a secondary transfer nip between the intermediate transfer device and the secondary transfer device. The secondary transfer device secondarily transfers the image from the intermediate transfer device onto a recording medium at the secondary transfer nip. At least one support shaft supports the intermediate transfer device. The at least one support shaft supports, on an identical axis, one lateral end and another lateral end of the secondary transfer device in a width direction of the recording medium.

Abstract: An image forming apparatus includes an image forming device, a reading device, and processing circuitry. The image forming device forms a first image on a first face of a recording medium and form a second image on a second face of the recording medium. The first face and the second face are on opposite sides of the recording medium. The reading device detects a shape of the recording medium. The processing circuitry corrects the second image to be formed on the second face of the recording medium with respect to the first image formed on the first face of the recording medium based on the shape of the recording medium.

Abstract: An image reading device includes a first scanner, a second scanner, and circuitry. The first scanner is configured to read a first side of a recording medium. The second scanner is configured to read a second side of the recording medium. The circuitry is configured to generate a first correction value to correct misalignment between the first side and the second side. The circuitry is configured to input a second correction value. The circuitry is configured to correct an image based on the first correction value and the second correction value.

Abstract: An image reading device includes a first scanner, a second scanner, and circuitry. The first scanner is configured to read a first side of a recording medium. The second scanner is configured to read a second side of the recording medium. The circuitry is configured to generate a first correction value to correct misalignment between the first side and the second side. The circuitry is configured to input a second correction value. The circuitry is configured to correct an image based on the first correction value and the second correction value.

Abstract: A deviation detection device to detect a deviation of a rotator includes a contact member disposed in contact with the rotator and configured to move, following a deviation of the rotator in a width direction of the rotator. The deviation detection device further includes a deviation detector configured to detect a direction of the deviation and a deviation amount of the rotator based on a displacement of the contact member, and a wear detector configured to detect a state in which an amount of wear of the contact member has reached a threshold.

Abstract: A belt deviation detection device detects lateral displacement of a rotary belt in a width direction of the belt. The belt deviation detection device includes a contact member in contact with the belt at a contact portion of the contact member, a biasing member configured to bias the contact member toward the belt to press the contact member against the belt, and a displacement detector configured to detect the displacement of the belt in the width direction of the belt. The contact member is configured to track the displacement of the belt in the width direction of the belt. The contact member is made of a metal material, and a hardening treatment is applied to at least the contact portion of the contact member.

Abstract: A deviation detection device to detect a deviation of a rotator includes a contact member disposed in contact with the rotator and configured to move, following a deviation of the rotator in a width direction of the rotator. The deviation detection device further includes a deviation detector configured to detect a direction of the deviation and a deviation amount of the rotator based on a displacement of the contact member, and a wear detector configured to detect a state in which an amount of wear of the contact member has reached a threshold.

Abstract: A belt deviation detection device detects lateral displacement of a rotary belt in a width direction of the belt. The belt deviation detection device includes a contact member in contact with the belt at a contact portion of the contact member, a biasing member configured to bias the contact member toward the belt to press the contact member against the belt, and a displacement detector configured to detect the displacement of the belt in the width direction of the belt. The contact member is configured to track the displacement of the belt in the width direction of the belt. The contact member is made of a metal material, and a hardening treatment is applied to at least the contact portion of the contact member.

Abstract: An image forming device, which is included in an image forming apparatus, includes an image reader, a sheet conveyance passage, a transparent body, an opposing body, and multiple curved opposing portions. The image reader is configured to read an image formed on a target object. The sheet conveyance passage is a passage through which the target object is conveyed. The transparent body is disposed between the sheet conveyance passage and the image reader. The opposing body is disposed facing the transparent body on a side opposite the image reader. The multiple curved opposing portions have respective outwardly curving reference planes. The multiple curved opposing portions are sequentially switched and located at a predetermined image reading position at which the multiple curved opposing portions face the transparent body with a gap through which the target object passes the predetermined image reading position.

Abstract: A position measurement reference sheet for image position measurement on a recording medium includes a body having a front face to face an image reading face of a reading device, a recording medium detection window in the body to measure a position of an end of the recording medium, and an image detection window in the body to measure a position of an image on the recording medium. The position measurement reference sheet is interposed between the image reading face and the recording medium.

Abstract: An image measurement sheet for measuring an image formed on a recording medium includes a sheet having a plurality of medium scan windows used for detecting the recording medium, a plurality of image scan windows used for detecting the image formed on the recording medium, and an information scan window used for detecting imaging condition information recorded on the recording medium with the image, the plurality of medium scan windows to be corresponded to a portion of sides and a corner of the recording medium, the plurality of image scan windows to be corresponded to a portion of the image formed on the recording medium, and the information scan window to be corresponded to the imaging condition information recorded on the recording medium.

Abstract: An image forming device, which is included in an image forming apparatus, includes an image reader, a sheet conveyance passage, a transparent body, an opposing body, and multiple curved opposing portions. The image reader is configured to read an image formed on a target object. The sheet conveyance passage is a passage through which the target object is conveyed. The transparent body is disposed between the sheet conveyance passage and the image reader. The opposing body is disposed facing the transparent body on a side opposite the image reader. The multiple curved opposing portions have respective outwardly curving reference planes. The multiple curved opposing portions are sequentially switched and located at a predetermined image reading position at which the multiple curved opposing portions face the transparent body with a gap through which the target object passes the predetermined image reading position.

Abstract: A duct that is attachable to a main body includes a flow passage to flow air, the flow passage including a flexible structure, and a ventilation opening at a first end of the flow passage. The ventilation opening and at least a part of flow passage are passable through a recess of a detachable device which detachable from the main body. A main body including the duct, the detachable device, and an airflow generation device is also provided.

Abstract: An image measurement sheet for measuring an image formed on a recording medium includes a sheet having a plurality of medium scan windows used for detecting the recording medium, a plurality of image scan windows used for detecting the image formed on the recording medium, and an information scan window used for detecting imaging condition information recorded on the recording medium with the image, the plurality of medium scan windows to be corresponded to a portion of sides and a corner of the recording medium, the plurality of image scan windows to be corresponded to a portion of the image formed on the recording medium, and the information scan window to be corresponded to the imaging condition information recorded on the recording medium.

Abstract: A scanning line adjuster, which is incorporated in an optical scanner and an image forming apparatus, includes an optical element, an attitude changer, and an optical element positioner. The optical element is disposed on an optical path extending from a light source to a scanned target object. The optical element has a positioning portion. The attitude changer changes an attitude of the optical element. The optical element positioner contacts the positioning portion to position the optical element. The optical element positioner contacts the positioning portion of the optical element in a direction perpendicular to a moving direction of the positioning portion of the optical element when the attitude changer changes the attitude of the optical element. The optical element positioner includes a contact end to contact the positioning portion. The contact end is made of a different material from the other part of the optical element positioner.

Abstract: A duct that is attachable to a main body includes a flow passage to flow air, the flow passage including a flexible structure, and a ventilation opening at a first end of the flow passage. The ventilation opening and at least a part of flow passage are passable through a recess of a detachable device which detachable from the main body. A main body including the duct, the detachable device, and an airflow generation device is also provided.

Abstract: A position measurement reference sheet for image position measurement on a recording medium includes a body having a front face to face an image reading face of a reading device, a recording medium detection window in the body to measure a position of an end of the recording medium, and an image detection window in the body to measure a position of an image on the recording medium. The position measurement reference sheet is interposed between the image reading face and the recording medium.

Abstract: A scanning line adjuster, which is incorporated in an optical scanner and an image forming apparatus, includes an optical element, an attitude changer, and an optical element positioner. The optical element is disposed on an optical path extending from a light source to a scanned target object. The optical element has a positioning portion. The attitude changer changes an attitude of the optical element. The optical element positioner contacts the positioning portion to position the optical element. The optical element positioner contacts the positioning portion of the optical element in a direction perpendicular to a moving direction of the positioning portion of the optical element when the attitude changer changes the attitude of the optical element. The optical element positioner includes a contact end to contact the positioning portion. The contact end is made of a different material from the other part of the optical element positioner.