An image forming apparatus includes: a feed tray that contains printing paper therein; a user authentication unit that authenticates a user who is permitted to print; a paper loading detection unit that detects printing paper loaded into the feed tray; a memory device that stores a user authenticated as a paper-supplementing user; a paper feeding mechanism that feeds the printing paper from the feed tray; a paper jam detection unit that detects a paper jam; and a controller that controls a print job. The controller, when a paper jam has occurred, determines whether or not the paper jam is due to the paper-supplementing user having loaded the printing paper in an improper manner. Upon determining that the paper jam is due to the paper-supplementing user having loaded the printing paper in an improper manner, the controller, subsequently when the paper-supplementing user uses, requests that a loading condition be checked.

A feeder includes: a mount board that moves vertically while allowing sheet-shaped media to be stacked thereon; a transport device that allows an uppermost one of the sheet-shaped media stacked on the mount board to be sucked by a suction portion to transport the uppermost sheet-shaped medium to a transporter and to feed the uppermost sheet-shaped medium to a destination; left and right edge air blowers that blow air to left and right edge portions, when viewed from an upstream side in a transportation direction, of upper ones of the sheet-shaped media stacked; and left and right detectors that are disposed on left and right sides of the suction portion at the same position in the transportation direction, and that individually detect downward or upward bend amounts of left and right edge portions of the uppermost sheet-shaped medium.

An image forming apparatus includes first and second light emitting units, a light receiving unit for receiving light of the first light emitting unit when it is reflected, and receiving light of the second light emitting unit when it is not reflected, to output a signal of a predetermined level, and a control unit for starting light emission of the first light emitting unit before a front end of a paper sheet reaches an area, stopping light emission of the first light emitting unit while starting light emission of the second light emitting unit before a rear end of the paper sheet passes the area, and detecting a length of the paper sheet based on time after the output signal becomes a predetermined level during light emission of the first light emitting unit until the output signal becomes the predetermined level during light emission of the second light emitting unit.

An image forming apparatus includes first and second light emitting units, a light receiving unit for receiving light of the first light emitting unit when it is reflected, and receiving light of the second light emitting unit when it is not reflected, to output a signal of a predetermined level, and a control unit for starting light emission of the first light emitting unit before a front end of a paper sheet reaches an area, stopping light emission of the first light emitting unit while starting light emission of the second light emitting unit before a rear end of the paper sheet passes the area, and detecting a length of the paper sheet based on time after the output signal becomes a predetermined level during light emission of the first light emitting unit until the output signal becomes the predetermined level during light emission of the second light emitting unit.

A medium conveying apparatus includes a moving mechanism to move the set guide, a guide pair including a first guide having a first opening and a second opening, and a second guide to regulate a vertical direction of the medium conveyance path, a light emitting element and a light receiving element located on an outside of the medium conveyance path with the first guide in between, and on the downstream side of the first opening and the second opening so as to be apart from the moving mechanism by a predetermined distance or more in the medium conveying direction, a first light guide which is bent so as to guide a light emitted from the light emitting element to the first opening, and a second light guide which is bent so as to guide the light incident from the second opening to the light receiving element.

A medium conveying apparatus includes a moving mechanism to move the set guide, a guide pair including a first guide having a first opening and a second opening, and a second guide to regulate a vertical direction of the medium conveyance path, a light emitting element and a light receiving element located on an outside of the medium conveyance path with the first guide in between, and on the downstream side of the first opening and the second opening so as to be apart from the moving mechanism by a predetermined distance or more in the medium conveying direction, a first light guide which is bent so as to guide a light emitted from the light emitting element to the first opening, and a second light guide which is bent so as to guide the light incident from the second opening to the light receiving element.

A sheet feeding device includes a sheet tray, a blower, a feeder, an illuminator, an imager, and circuitry. The sheet tray stacks sheets. The blower blows air to the sheets stacked on the sheet tray and floats an uppermost sheet of the sheets. The feeder feeds the uppermost sheet. The illuminator illuminates the uppermost sheet floating. The imager captures an image including the uppermost sheet illuminated by the illuminator. The circuitry adjusts an imaging condition based on the image captured by the imager.

A conveyor includes a conveyance roller to convey a conveyed object, a pair of roller supports opposing to each other and supporting both ends of the conveyance roller in an axial direction thereof, a position sensor to detect a position of the conveyed object, and a sensor support supporting the position sensor. Each of the pair of roller supports has an insertion hole into which the sensor support is inserted. The insertion hole determines a position of the sensor support in a direction intersecting an insertion direction of the sensor support. The sensor support includes a positioning portion determining the position of the sensor support with respect to at least one of the pair of roller supports. The positioning portion determines the position of the sensor support in the insertion direction, a direction opposite to the insertion direction, and a rotational direction about an axis along the insertion direction.

An image forming apparatus includes a first unit, a second unit fixed to the first unit at a portion upstream of the first unit in a conveyance direction in which the sheet is conveyed, and an electric board. In the image forming apparatus, a disposition of the electric board is restricted by the first unit and the second unit.

An image forming apparatus includes a first unit, a second unit fixed to the first unit at a portion upstream of the first unit in a conveyance direction in which the sheet is conveyed, and an electric board. In the image forming apparatus, a disposition of the electric board is restricted by the first unit and the second unit.