A medium conveying apparatus includes a medium tray, a feed roller, an upper guide, a movement sensor including an arm movably provided by the fed medium on the upper guide and on an upstream side of the feed roller, to generate a movement amount signal corresponding to a movement amount of the arm, a medium sensor to detect a presence of the medium at a predetermined position of the medium tray, a processor to determine whether a feeding abnormality of the medium has occurred based on the movement amount signal, detect a size of the medium placed on the medium tray based on a detection result by the medium sensor, and stop feeding of the medium by the feed roller when the processor determines that the feeding abnormality of the media has occurred and the detected size of the media is equal to or less than a predetermined size.

A feeding device includes a loading portion, a lifting mechanism, a conveying unit, a sheet detector, a near-end detector, and process circuitry. The loading portion stacks a plurality of sheets. The lifting mechanism lifts the loading portion. The conveying unit conveys the sheets on the loading portion. The sheet detector detects presence or absence of the sheets on the loading portion at a specified height position. The sheet count detector detects a number of sheets conveyed by the conveying unit. The near-end detector detects a near-end state in which a stack height of the sheets on the loading portion is a specified value or less. The process circuitry controls the lifting mechanism based on a detection result of the sheet detector before the near-end state is detected, and controls the lifting mechanism based on a detection result of the sheet count detector after the near-end state is detected.

A feeding device includes a loading portion, a lifting mechanism, a conveying unit, a sheet detector, a near-end detector, and process circuitry. The loading portion stacks a plurality of sheets. The lifting mechanism lifts the loading portion. The conveying unit conveys the sheets on the loading portion. The sheet detector detects presence or absence of the sheets on the loading portion at a specified height position. The sheet count detector detects a number of sheets conveyed by the conveying unit. The near-end detector detects a near-end state in which a stack height of the sheets on the loading portion is a specified value or less. The process circuitry controls the lifting mechanism based on a detection result of the sheet detector before the near-end state is detected, and controls the lifting mechanism based on a detection result of the sheet count detector after the near-end state is detected.

An image forming apparatus includes a detection sensor to irradiate light to a recording medium passing through a printing path, and detect an amount of light, a driving device to move a cleaning member to a cleaning region overlapping the printing path to clean a light window of the detection sensor, and a processor to confirm a position of the cleaning member based on the amount of light detected by the detection sensor and control the driving device to move the cleaning member based on the confirmed position.

A sheet material detecting device includes a leading end flag, a pair of middle size flags, a pair of large size flags which take stand-by positions and operating positions by contacting a sheet, respectively. Each of middle size flags changes from the stand-by position to the operating position linking with changing to the operating position of each of large size flags. A link is moved from a first position to a second position in a case that both of middle size flags take the operating positions and is restricted in movement to the second position in a case that both of middle size fags do not take the operating portions. A controller detects a width of the sheet base on a timing of the operating position of the leading end flag and a timing of movement of the link from the first position to the second position.

A sheet material detecting device includes a leading end flag, a pair of middle size flags, a pair of large size flags which take stand-by positions and operating positions by contacting a sheet, respectively. Each of middle size flags changes from the stand-by position to the operating position linking with changing to the operating position of each of large size flags. A link is moved from a first position to a second position in a case that both of middle size flags take the operating positions and is restricted in movement to the second position in a case that both of middle size fags do not take the operating portions. A controller detects a width of the sheet base on a timing of the operating position of the leading end flag and a timing of movement of the link from the first position to the second position.

A paper conveying device, used in a paper processing device to perform predetermined processing on paper, includes a conveying portion, a holding portion, a detection portion, and a control portion. The conveying portion conveys, in a conveying direction, the paper to a processing portion of the paper processing device. The holding portion is disposed downstream of the processing portion in the conveying direction and holds the paper processed by the paper processing device. The detection portion detects a change of an orientation of the paper held by the holding portion. The control portion releases the paper held by the holding portion in a case where an amount of the detected orientation change reaches a predetermined amount.

A paper conveying device, used in a paper processing device to perform predetermined processing on paper, includes a conveying portion, a holding portion, a detection portion, and a control portion. The conveying portion conveys, in a conveying direction, the paper to a processing portion of the paper processing device. The holding portion is disposed downstream of the processing portion in the conveying direction and holds the paper processed by the paper processing device. The detection portion detects a change of an orientation of the paper held by the holding portion. The control portion releases the paper held by the holding portion in a case where an amount of the detected orientation change reaches a predetermined amount.

Various embodiments disclose a method of detecting a media jam in a printer. The method includes causing a sensor unit of the printer to generate a sensor signal indicative of a reflectance characteristic associated with a surface of a roller of the printer. Further, the method includes receiving the sensor signal from the sensor unit of the printer and comparing the reflectance characteristic to a threshold reflectance characteristic associated with the roller. Furthermore, in response to the comparison, the method includes generating an output signal to indicate whether the media jam has occurred. For example, a first output signal indicates unsuccessful passage of a media along a media path of the printer, when the reflectance characteristic exceeds the threshold reflectance characteristic and a second output signal indicates successful passage of the media along the media path, when the reflectance characteristic is equal to or below the threshold reflectance characteristic.

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.