A sheet conveying apparatus includes a tray having a plurality of sheets, a feeder to successively convey sheets stacked on the tray, a controller, and a double-feed sensor to detect double feed when the feeder conveys a plurality of sheets in an overlapping manner. When a double-feed length, which corresponds to a length, in a conveyance direction of the sheet, of a region in which the double feed has been detected by the double-feed sensor, is larger than a predetermined distance, the controller determines that the double feed has occurred. When the double-feed length is smaller than the predetermined distance and a sheet size is smaller than a predetermined size, the controller determines that the double feed has occurred. When the double-feed length is smaller than the predetermined distance and the sheet size is larger than the predetermined size, the controller determines that the double feed has not occurred.

An image processing apparatus includes a selection unit, a determination unit, and a control unit to set candidates to be selected by the selection unit. If determination unit determines that there is not a set of a size and an orientation of a document of which the orientation cannot be correctly determined, the control unit sets, as selection unit selection candidates, candidates of sets of sizes and orientations of a plurality of documents. If the determination unit determines that there is a set of a size and an orientation of a document of which the orientation cannot be correctly determined, the control unit sets, as selection unit selection candidates, candidates obtained by excluding the set of the size and the orientation of the document of which the orientation cannot be correctly determined from the candidates of the sets of the sizes and the orientations of the plurality of documents.

In a sheet conveyance apparatus a control unit controls lifting and lowering of a sheet supporting portion by a lifting unit and executes a mixed feeding in one of a plurality of modes including a first mode and a second mode. The mixed feeding is an operation in which a plurality of sheets having different lengths in a width direction orthogonal to a feed direction of a sheet feeding unit are fed by the feeding unit, wherein in the first mode, the control unit causes the lifting unit to move the supporting portion from the second position to the first position based on an instruction to start sheet feeding, and in the second mode, the control unit causes the lifting unit to move the supporting portion from the second position to the first position based on a detection of a sheet by the detection unit.

To provide a sheet conveyance device capable of preventing degradation in quality of conveying a sheet and image quality even when a stiffness of the sheet is different between a sheet conveyance direction and a sheet width direction. A sheet conveyance device of an image forming apparatus includes an image forming part that conveys a sheet along a conveyance path; and a stiffness acquisition part that acquires a stiffness of the sheet in a first direction including a component in the sheet conveyance direction by bending the sheet in the first direction, and acquires a stiffness of the sheet in a second direction including a component in the sheet width direction orthogonal to the sheet conveyance direction by bending the sheet in the second direction.

A document feeder includes a mode selector, at least two document sensors, and a feeding determiner. The mode selector receives selection of either a normal mode for feeding documents having the same size or a mixed loading mode for feeding documents having different sizes. The document sensors are arranged at an interval in a width direction of the documents, and detect the documents. The feeding determiner performs, based on results of the detection by the document sensors, a size determination to determine a size of a document being fed and a skew determination to determine whether or not the document being fed is skewed. The feeding determiner performs the skew determination when the normal mode has been selected and performs the size determination when the mixed loading mode has been selected.

A document reading apparatus having a display unit and a placement section on which plural documents is to be placed includes a conveyance unit and a reading unit. The conveyance unit conveys a document placed on the placement section. The reading unit reads a document conveyed by the conveyance unit and generates image data. Based on at least a reading mode being set on the document reading apparatus of reading a plurality of documents of a plurality of different sizes in a single job by the reading unit, first prompting information that prompts placement of the plurality of documents at a center of the placement section in a direction perpendicular to a document conveyance direction in which the conveyance unit conveys the plurality of documents is displayed on the display unit.

An image processing apparatus includes a motor, a sheet feeding roller, a separation roller, a conveyance roller, a first clutch set provided in a transmission path of a driving force transmitted from the motor to the sheet feeding roller, and a second clutch set provided in a transmission path of a driving force transmitted from the motor to the separation roller. The first clutch set includes a first one-way clutch and a first two-way clutch, and the second clutch set includes a second one-way clutch and a second two-way clutch. A maximum value of a first play angle set between a first transmission portion and a first transmitted portion in the first two-way clutch is larger than a maximum value of a second play angle set between a second transmission portion and a second transmitted portion in the second two-way clutch.

A sheet transport device includes a sheet transport unit, a detector, and a releasing unit. The sheet transport unit transports a sheet by nipping the sheet in a nip between multiple pairs of transport rollers arranged in a sheet width direction intersecting a sheet transport direction. The detector detects a size of the transported sheet. The releasing unit releases the nip of one or more of the pairs of transport rollers outside a transport region of the sheet based on the size of the sheet detected by the detector.

An image forming apparatus includes: a conveyor that transports a sheet; an image former that forms an image on front and back surfaces of the sheet being transported in a transportation path and forms marks on the front and back surfaces; a reader that comprises a first line sensor that is disposed on a front surface side and reads the front surface; and a second line sensor that is disposed on a back surface side and reads the back surface; and a controller that: calculates a positional deviation between the images formed on the front and back surfaces based on positions of the marks on the front surface read by the first line sensor and positions of the marks on the back surface read by the second line sensor, and controls the image former to adjust positions of the images formed on the front and back surfaces.

Setting conditions related to reading of an image of a document are registered in association with a user according to input by a user. When a user is identified, the priority order is determined so that a setting condition corresponding to the identified user is prioritized over a setting condition not corresponding to the user among the registered setting conditions, and the setting condition information indicating the setting conditions in the determined priority is displayed. The image is read under the setting condition based on the setting condition information selected according to the input by the user of the setting condition information indicating the displayed setting conditions.