A document feeding device includes a document placement unit at which a document is placed, a feeding roller for feeding the document, and a ranging sensor for measuring a distance to the document located most upward on the document placement unit. A control unit stops feeding the document by the feeding roller based on post-processing distance data obtained by statistically processing time series data of the distance measured by the ranging sensor.

An image forming apparatus includes a sheet separation device, a first sheet feeder, a second sheet feeder, an image forming device, and circuitry. The sheet separation device is configured to separate a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet. The first sheet feeder is configured to feed the two-ply sheet. The second sheet feeder is configured to feed an inner sheet to be inserted between the two sheets. The image forming device is configured to form an image on a surface of the inner sheet. The circuitry is configured to cause the first sheet feeder to feed the two-ply sheet, perform a sheet separating operation on the two-ply sheet and cause the second sheet feeder to start feeding the inner sheet before completion of the sheet separating operation on the two-ply sheet.

An image forming apparatus forming an image on a sheet, including: an exterior member movable with respect to an apparatus main body; a locking portion locking the exterior member to the apparatus main body such that the exterior member is not moved with respect to the apparatus main body; a display portion which is disposed on the exterior member and displays a state of the locking portion; and a light source turning on the display portion, in which the display portion includes a thin portion which is a part of the exterior member, has a thickness less than thicknesses of other portions of the exterior member, and transmits light from the light source.

An image forming apparatus forming an image on a sheet, including: an exterior member movable with respect to an apparatus main body; a locking portion locking the exterior member to the apparatus main body such that the exterior member is not moved with respect to the apparatus main body; a display portion which is disposed on the exterior member and displays a state of the locking portion; and a light source turning on the display portion, in which the display portion includes a thin portion which is a part of the exterior member, has a thickness less than thicknesses of other portions of the exterior member, and transmits light from the light source.

A sheet feeding device includes a sheet loading portion which is capable of elevating operation and on which a sheet is loaded, a feeding member for feeding the sheet loaded on the sheet loading portion, the feeding member being capable of elevating movement between a contacting position in contact with the sheet and a distanced position distanced upward from the sheet, and a control portion that controls the elevating operation of the sheet loading portion and the elevating movement of the feeding member. When the feeding member at the contacting position moves to the distanced position, the feeding member is distanced upward from the sheet loaded on the sheet loading portion after the sheet loading portion starts a descending operation.

According to some examples, a skew detection device comprises a first roller rotatable around a first axis, a second roller rotatable around a second axis, a first sensor, and a second sensor. The first sensor measures a first rotation parameter from the first roller and the second sensor measures a second rotation parameter from the second roller. A movement of a print media over the device rotates the first contact roller and the second roller, and a controller determines a skew of the print media based on the first and second rotation parameters captured by the first sensor and the second sensor.

A sheet processing apparatus includes a plurality of folding devices, a control unit that controls a job involving a folding process, and an input unit that accepts settings for the job from a user. The input unit accepts, from the user, specification of a priority preference out of a plurality of predetermined preferences related to the folding process. The control unit selects, out of the plurality of folding devices, a folding device that can perform the folding process with the settings for the job made by the user as a target folding device. If a plurality of target folding devices are present, then based on the priority preference, the control unit determines, out of the plurality of target folding devices, a folding device with which to perform the folding process.

An image forming apparatus includes a sheet storage unit including a sheet tray on which one or more sheets are to be stacked, a sensor configured to detect that the sheet storage unit is being operated, and a processor configured to execute a predetermined process after the sensor detects that the sheet storage unit has been operated, and a predetermined condition relating to an occurrence of the sheet conveyance error is satisfied.

A sheet conveying apparatus capable of continuing conveyance of sheets without causing a jam even when a switching member performs an operation for switching a conveyance path again. A switching member is disposed at a branching point of a conveyance path through which the sheet is conveyed by a conveying unit, and is operated by a drive unit for witching a destination of conveyance of the sheet. A controller causes the drive unit to operate the switching member, and performs a checking operation for checking a state of the drive unit based on an output from a sensor that detects a state of the switching member. The controller controls a sheet conveyance interval between a first sheet conveyed by the conveying unit and a second sheet conveyed following the first sheet, according to a result of the checking operation.

A sheet conveying apparatus capable of continuing conveyance of sheets without causing a jam even when a switching member performs an operation for switching a conveyance path again. A switching member is disposed at a branching point of a conveyance path through which the sheet is conveyed by a conveying unit, and is operated by a drive unit for witching a destination of conveyance of the sheet. A controller causes the drive unit to operate the switching member, and performs a checking operation for checking a state of the drive unit based on an output from a sensor that detects a state of the switching member. The controller controls a sheet conveyance interval between a first sheet conveyed by the conveying unit and a second sheet conveyed following the first sheet, according to a result of the checking operation.