Provided is a sheet conveyance apparatus armored with a housing, the sheet conveyance apparatus includes: a sheet conveyor that feeds a sheet to a downstream side in a direction of conveyance; a conveyance guide that guides the sheet to be conveyed; an ultrasonic sensor that detects the sheet guided by the conveyance guide; and a shield member that is conductive, wherein the ultrasonic sensor includes: a transmitter that transmits an ultrasonic wave having a predetermined frequency; and a receiver that receives the ultrasonic wave, the transmitter and the receiver are arranged along the conveyance guide, and the shield member is disposed between the housing and the receiver in a sheet-face perpendicular direction at an ultrasonic-irradiation position of the sheet being conveyed, the shield member covering an entirety of the receiver in plan view in the sheet-face perpendicular direction.

A theoretical threshold corresponding to a transport path is set, and a control unit acquires a calculation value calculated based on a detection result of double feeding detection unit and a transport length of a document, determines occurrence of double feeding when the calculation value is greater than the theoretical threshold (step S120), and determines non-occurrence of double feeding when the calculation value is smaller than the theoretical threshold. In addition, if a non-detection period for double feeding occurs (step S110), the control unit sets a cumulative value in step S115. As a result, detection of double feeding is ended in a short period while a document is being transported, and in a case that double feeding is no longer detected, determination of double feeding will not be made.

A theoretical threshold corresponding to a transport path is set, and a control unit acquires a calculation value calculated based on a detection result of double feeding detection unit and a transport length of a document, determines occurrence of double feeding when the calculation value is greater than the theoretical threshold (step S120), and determines non-occurrence of double feeding when the calculation value is smaller than the theoretical threshold. In addition, if a non-detection period for double feeding occurs (step S110), the control unit sets a cumulative value in step S115. As a result, detection of double feeding is ended in a short period while a document is being transported, and in a case that double feeding is no longer detected, determination of double feeding will not be made.

A conveying apparatus includes a conveyor and a conveyed object receptor. The conveyor includes a conveyance surface facing downward and configured to convey a conveyed object having a sheet-like shape. The conveyed object receptor is arranged below the conveyor and configured to receive the conveyed object having fallen from the conveyor.

A sheet feeding apparatus for feeding sheets is provided with a multi feed detecting section for detecting multi feed of conveyed sheets in a predetermined detection position of a conveyance path, and first and second discharge sections to which multi-fed sheets with the multi feed detected are discharged, and corresponding to one of a front end position of the multi-fed sheets at the time the multi feed detecting section detects the multi feed of sheets, a sheet storage state of the second discharge section, sheet storage states of the first and second discharge sections, a size of sheets and weighing, selects one of the first and second discharge sections to discharge the multi-fed sheets to the selected discharge section.

A sheet feeding apparatus for feeding sheets is provided with a multi feed detecting section for detecting multi feed of conveyed sheets in a predetermined detection position of a conveyance path, and first and second discharge sections to which multi-fed sheets with the multi feed detected are discharged, and corresponding to one of a front end position of the multi-fed sheets at the time the multi feed detecting section detects the multi feed of sheets, a sheet storage state of the second discharge section, sheet storage states of the first and second discharge sections, a size of sheets and weighing, selects one of the first and second discharge sections to discharge the multi-fed sheets to the selected discharge section.

A media feeding apparatus includes a media mounting section, a first feed roller, a media pressing section for pressing media sheets against the first feed roller, and a pressing force adjuster for adjusting the pressing force of the media pressing section. The controller sets the pressing force of the media pressing section to first pressing force and drives the first feed roller and the second feed roller in a forward rotation direction, and in a case in which the first detector detects a passage of a leading edge of the media sheet and the second detector detects no passage of the leading edge of the media sheet after predetermined first set time has passed, the controller continues the rotation of the first feed roller and the second feed roller with second pressing force of the media pressing section greater than or equal to the first pressing force.

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 includes a tray having a plurality of sheets, a feeder to successively convey sheets stacked on the tray, a controller, and a double-feed sensor to detect double feed when the feeder conveys a plurality of sheets in an overlapping manner. When a double-feed length, which corresponds to a length, in a conveyance direction of the sheet, of a region in which the double feed has been detected by the double-feed sensor, is larger than a predetermined distance, the controller determines that the double feed has occurred. When the double-feed length is smaller than the predetermined distance and a sheet size is smaller than a predetermined size, the controller determines that the double feed has occurred. When the double-feed length is smaller than the predetermined distance and the sheet size is larger than the predetermined size, the controller determines that the double feed has not occurred.

A sheet conveying apparatus includes a tray having a plurality of sheets, a feeder to successively convey sheets stacked on the tray, a controller, and a double-feed sensor to detect double feed when the feeder conveys a plurality of sheets in an overlapping manner. When a double-feed length, which corresponds to a length, in a conveyance direction of the sheet, of a region in which the double feed has been detected by the double-feed sensor, is larger than a predetermined distance, the controller determines that the double feed has occurred. When the double-feed length is smaller than the predetermined distance and a sheet size is smaller than a predetermined size, the controller determines that the double feed has occurred. When the double-feed length is smaller than the predetermined distance and the sheet size is larger than the predetermined size, the controller determines that the double feed has not occurred.