A sheet feeding apparatus includes an apparatus body, an opening/closing member openable/closable with respect to the apparatus body and including a support portion supporting a sheet in a condition in which the opening/closing member is opened. The sheet supported by the support portion is fed by a feed portion. The opening/closing member is provided with a detection portion configured to detect the sheet on the support portion. The detection portion is disposed at a position where the detection wave emitted from the detection portion is not detected in a condition in which the opening/closing member is closed.

A sheet feeding apparatus includes an apparatus body, an opening/closing member openable/closable with respect to the apparatus body and including a support portion supporting a sheet in a condition in which the opening/closing member is opened. The sheet supported by the support portion is fed by a feed portion. The opening/closing member is provided with a detection portion configured to detect the sheet on the support portion. The detection portion is disposed at a position where the detection wave emitted from the detection portion is not detected in a condition in which the opening/closing member is closed.

A sheet conveying apparatus includes a first roller, a first guide, a second guide, a second roller, and a third roller. The first guide is configured to guide the sheet conveyed by the first roller and includes a first guide surface and a first edge portion located downstream of the first guide surface in a sheet conveying direction. The second guide, disposed downstream of the first guide, includes a second guide surface and a second edge portion located upstream of the second guide surface. The second roller is disposed downstream of the first roller and above the first roller. The third roller is disposed at a position more proximate to the second guide surface than the second roller. When projected on a cut plane orthogonal to an axis of the third roller, at least of a part of the second edge portion overlaps the third roller.

A sheet conveying apparatus includes a first roller, a first guide, a second guide, a second roller, and a third roller. The first guide is configured to guide the sheet conveyed by the first roller and includes a first guide surface and a first edge portion located downstream of the first guide surface in a sheet conveying direction. The second guide, disposed downstream of the first guide, includes a second guide surface and a second edge portion located upstream of the second guide surface. The second roller is disposed downstream of the first roller and above the first roller. The third roller is disposed at a position more proximate to the second guide surface than the second roller. When projected on a cut plane orthogonal to an axis of the third roller, at least of a part of the second edge portion overlaps the third roller.

A sheet tray provided with first and second trays respectively having first and second supporting surfaces. The second tray slidably assembled, in a first direction, to the first tray. The first and second supporting surfaces are configured to support sheets thereon. The first tray and the second tray have a first guide portion and a second guide portion which are formed at central parts, in a second direction perpendicular to the first direction, respectively. The second guide portion is configured to slidably contact the first guide portion to guide the slide movement of the second tray. A first separation regulating part formed on the first guide portion, and a second separation regulating part formed on the second guide portion are configured to engage with each other in the vertical direction to prevent separation of the first and second trays in the vertical direction, exceeding a particular dimension.

A coupling mechanism of the present disclosure includes a drive transmission member, a coupling member and a biasing member. The drive transmission member includes a shaft portion and an engagement pin. The coupling member includes a plurality of engagement protrusions and a holding protrusion which is smaller than the engagement protrusion. The holding protrusion makes contact with the engagement pin in a state where the engagement pin makes contact with the pressing surface. A load in a reverse rotation direction is applied from the holding protrusion to the engagement pin when the coupling member is reversely rotated.

An optional device of the present disclosure is attachable and detachable with respect to an image forming apparatus via a connection member fitted to a side face of a main body of the optional device. The connection member includes a shaft, a connector, and a lock member. The shaft is supported by the main body to be slidable in an axial direction. The connector is fixed to the shaft and coupled to the image forming apparatus. The lock member is capable or restricting movement of the shaft in the axial direction. A position of the connector is adjusted by releasing the restriction placed on the shaft by the lock member and then sliding the shaft in the axial direction.

A motor control unit controls a driving current that flows through a coil of a motor to be driven, by controlling a PWM signal supplied to an H bridge circuit constituted by FETs. A current value generation unit detects a driving current based on a voltage that occurs across a current detection resistor, and corrects a detection value by using a first or second correction value. The current value generation unit, if the driving current is detected in the H period of the PWM signal, corrects the detection value by using the first correction value, and if the driving current is detected in the L period of the PWM signal, corrects the detection value by using the second correction value that has a polarity different from a polarity of the first correction value.

A motor control unit controls a driving current that flows through a coil of a motor to be driven, by controlling a PWM signal supplied to an H bridge circuit constituted by FETs. A current value generation unit detects a driving current based on a voltage that occurs across a current detection resistor, and corrects a detection value by using a first or second correction value. The current value generation unit, if the driving current is detected in the H period of the PWM signal, corrects the detection value by using the first correction value, and if the driving current is detected in the L period of the PWM signal, corrects the detection value by using the second correction value that has a polarity different from a polarity of the first correction value.

A detachable document handler (having an outer casing) has a transparent platen as the casing bottom, and a document tray as the casing top. A moveable internal scanner is located within the outer casing, and is positioned to move past the transparent platen within the outer casing. The moveable internal scanner is in a location within the outer casing to optically scan items external to the outer casing through the transparent platen. A sheet feeder system are also within the outer casing. The sheet feeder system (within the outer casing) is positioned adjacent the document tray in a location to feed sheets from the document tray, internally within the outer casing, past the moveable internal scanner, and back to the document tray. A transparent member within the outer casing is located between the sheet feeder system and the moveable internal scanner.