An automatic document feeder (300) includes a housing (301), conveyance roller pairs (313 to 317), and a pressure releasing mechanism. The housing (301) is openably/closably attached to a main body of an image forming apparatus. The conveyance roller pairs (313 to 317) pinch an original document sheet with pressure and feed the original document sheet. The pressure releasing mechanism detaches one rollers (313b to 317b) of the conveyance roller pairs (313 to 317) from the other rollers (313a to 317a) in conjunction with an operation of opening the housing 301 against the main body.

A first surface of a first sheet has a second image formed in advance. An image forming system generates reference data based on a result of reading an image on the first surface of the first sheet on which a first image is not formed, generates first image data that represents a result of reading an image on the first surface of the first sheet having the first image formed on the first surface, and determines, based on the reference data and the first image data, a relative position between the first image and the second image on the first surface of the first sheet.

A power switching device includes a translation mechanism, an active mechanism, and a transmission mechanism. The translation mechanism includes a rack. The active mechanism includes an active gear and a driver. The active gear connects with a first functional mechanism, and the driver drives the active gear to rotate in a first direction or a second direction. The transmission mechanism connects with a second functional mechanism. The active gear is switched between a first position and a second position. In the first position, the active gear is connected to the transmission mechanism and rotates in the first direction to drive the transmission mechanism to rotate, thereby driving the second functional mechanism to operate. In the second position, the active gear meshes with the rack and rotates in the first direction or the second direction to reciprocate on the rack so as to drive the first functional mechanism to operate.

A sheet conveying device includes a sheet placement table, a sheet discharge table, a conveyance mechanism, raising/lowering mechanism, and a raising/lowering control portion. The sheet discharge table is located below the sheet placement table. The conveyance mechanism conveys a sheet placed on the sheet placement table onto the sheet discharge table via an execution position at which image processing is executed by an image processing portion. The raising/lowering mechanism raises and lowers the sheet placement table. The raising/lowering control portion controls the raising/lowering mechanism to raise and lower the sheet placement table to a target position that is determined in accordance with a size of the sheet on the sheet discharge table.

Method and systems of automated document processing described herein include activating in sequence a plurality of illumination modules of an illumination source to illuminate a document, where the plurality of illumination modules are located at different positions relative to the document. The document can be imaged each time the document is illuminated by an illumination module to provide a plurality of images. A shadow profile of the document can be obtained based on the plurality of images. One or more of a boundary of the document and presence of a fastener attached to the document can be identified using the shadow profile. Any fasteners present may be removed using a robot arm.

An image reading apparatus includes a scanner structured to reads an image formed on a medium which is conveyed; a calibration member located opposite to the scanner and structured to reflect irradiation light to be radiated to the medium when reading an image; a first roller arranged in a fixed position and structured to guide a conveying direction of the medium passing between the scanner and the calibration member; and a second roller arranged in a variable position in accordance with the stiffness of the medium and structured to guide the conveying direction of the medium passing between the scanner and the calibration member.

An image reading apparatus includes a document supporter, a guide, a carriage, and a reader. The carriage has a recessed portion. A first protrusion, a second protrusion, a third protrusion, a fourth protrusion, a fifth protrusion, and a sixth protrusion are provided on the recessed portion. Each of the first protrusion, the second protrusion, the third protrusion, and the fourth protrusion has a distal end portion in a protruding direction thereof, and the distal end portion is in contact with the guide when the carriage is mounted on the guide. A protruding amount of each of the fifth protrusion and the sixth protrusion in a protruding direction thereof is less than that of each of the first protrusion, the second protrusion, the third protrusion, and the fourth protrusion.

A medium feeding device includes a lower portion unit in which a feeding roller is provided, and an upper portion unit in which a separating roller is provided and which is connected to the lower portion unit so as to be openable and closable. The lower portion unit has a cover member which covers a holding portion of the feeding roller while exposing a portion of the feeding roller to the transport path, and the cover member is configured to be removable in a direction including a component directed toward an upstream side in the transport direction by being attachable to and detachable from the lower portion unit.

A sheet conveying device, including: a conveyor; a first supporter configured such that, when located at its closed position, a first surface thereof partially forms an exterior surface of the device and such that, when located at its open position, a second surface thereof supports the sheet to be supplied to the conveyor; a second supporter configured such that, when located at its closed position, a first surface thereof partially forms the exterior surface of the device and such that, when located at its open position, a second surface thereof supports the sheet output from the conveyor; and a link configured such that, when the first supporter is moved from the closed position to the open position, the link transmits a force from the first supporter to the second supporter and thereby moves the second supporter from the closed position to the open position in conjunction with the first supporter.

A medium feeder includes a medium mounter, a pair of edge guides, and a sheet number limiter. The medium mounter has a mounting surface on which a medium to be fed is placed. The pair of edge guides is provided at the medium mounter to guide side edges of the medium in a direction that intersects with a feeding direction in which the medium is fed. The sheet number limiter is provided at the pair of edge guides to limit the number of media mountable on the medium mounter. The sheet number limiter has an extension that extends in a feeding direction of the medium such that a distance between the extension and the mounting surface increases downstream.