Provided is a sheet conveying device capable of suppressing the recurrence of overlapped feeding in accordance with the detection of overlapped feeding. The sheet conveying device includes a paper-supply roller and a conveying roller. A sheet-detecting unit detects a leading edge position of a sheet. An overlapped-feeding-detecting unit detects overlapped-feeding of sheets. An overlapped-feeding-distance-calculating unit, based on detection results, calculates an overlapped-feeding distance in which sheets are overlapped. A conveyance-control unit causes the paper-supply roller to stop at a timing when a position separated a set length in a sheet-conveyance direction from a sheet trailing edge reaches the paper-supply roller. The conveyance-control unit, in a case where detection of overlapped feeding by the overlapped-feeding-detecting unit occurs a plurality of times, extends the set length based on the overlapped-feeding distance.

A sheet feeding device comprises sheet storage for storing a sheet, a merging conveying unit for feeding the sheet from the sheet storage to an image forming apparatus, a transmitting element for transmitting an ultrasonic signal to the sheet conveyed on the merging conveying unit, and a receiving element for receiving the ultrasonic signal having passed through the sheet and outputting an output signal according to strength of the received ultrasonic signal. When the sheet is a Japanese paper, the sheet feeding device detects double feeding of the sheet according to an average value of a plurality of the output signals and variation in a plurality of the output signals obtained for the one sheet. If the sheet is not double fed, the sheet is fed to the image forming apparatus. If the sheet is double fed, the sheet is discharged to the escape tray.

A scanning device includes at least one motor, an input tray, a pickup roller, a separation roller module, an ultrasonic sensor, a scanning module, a path switcher and a controller. The pickup roller is connected with the at least one motor. The separation roller module is connected with the at least one motor. The ultrasonic sensor includes an ultrasonic emitter and an ultrasonic receiver. The ultrasonic sensor is used for sensing that a single paper or multiple papers are fed in. The scanning module is used for scanning a plurality of papers. The path switcher is connected with the at least one motor. The at least one motor is capable of driving the path switcher to be switched to a first position and a second position. The controller is connected with the at least one motor and the ultrasonic sensor.

A medium feeding device includes an imaging unit which images a medium tip end portion from a position of facing a face of the medium on a downstream side of a nipping position of the medium using a feeding unit and a separating unit; and a determining unit which determines whether or not there is transport disorder by evaluating a state of a boundary between a path member which forms a medium transport path and a medium tip end from image data obtained by the imaging unit, in which the determining unit sets a rectangular determining region including at least a part of the boundary with respect to the image data, and determines whether or not there is transport disorder based on a length of a boundary in the determining region.

A machine for folding sheets receives a stream of sheets. A first folding unit is followed by a further unit. The first folding unit has at least one buckle plate and at least two folding rollers to fold the sheets. A monitoring device checks the stream for defects. A control unit activates a removal device for removing waste products when a defect is detected. The monitoring device is disposed at the entry region of the buckle plate and monitors the stream in the buckle plate. The removal device is disposed downstream of the first folding unit and upstream of the further unit. The system, which is suitable for industrial folding machines, reliably detects unusable waste products in the folding process even before production might be affected.

The automatic document feeder includes a multi-feed detection sensor unit, a sensor control unit, and a control board on which the sensor control unit is mounted. The multi-feed detection sensor unit includes a transmission board on which a transmission sensor and a detection circuit of a drive current of the transmission sensor are mounted, a reception board on which a reception sensor and an amplifier circuit of a reception signal of the reception sensor are mounted, and a relay board on which a drive circuit of the transmission sensor is mounted. The sensor control unit stores first fault information indicating that the relay board is disconnected if the relay board is disconnected, stores second fault information indicating that the reception board is at fault if an output value of the amplifier circuit is equal to or less than a first threshold, stores third fault information indicating that the transmission board is at fault if the detection circuit does not detect the drive current, and stores fourth fault information indicating that the transmission sensor or the reception sensor is damaged if the output value of the amplifier circuit is equal to or less than a second threshold. If the fault information is stored, the sensor control unit transmits, to an image forming apparatus, an instruction signal for causing the fault information to be displayed.

A feeding apparatus includes a feeding member, first and second conveying members, a separation member, and drive and control units. The feeding member feeds a recording material placed on a tray. The separation member and the first conveying member form a nip portion and separates recording materials at the nip portion. The second conveying member conveys a conveyed recording material. The drive unit drives at least the feeding member. The control unit controls to feed first and second recording materials such that a second recording material front edge passes the nip portion before a first recording material rear edge passes the nip portion, and controls to stop the second recording material after the second recording material front edge has passed the nip portion such that the first recording material rear edge reaches the second conveying member before the second recording material front edge reaches the second conveying member.

A transporting apparatus includes a speaker and a microphone that are arranged opposite to each other with respect to a transportation path, and a controller that controls a transportation mechanism based on microphone output obtained by causing the microphone to acquire a sound emitted by the speaker. The controller uses the microphone to acquire the sound emitted by the speaker and changes, based on the microphone output, at least any of a time period during which the speaker is driven, output from the speaker, and the microphone output.

A medium feeding device includes a feed roller that feeds a medium from a medium placement unit on which the medium is placed a separation roller that nips the medium between the feed roller and the separation roller to separate the medium, a motor that applies a rotational torque to the separation roller, and a control unit that controls the motor. The rotational torque is transmitted to the separation roller from the motor not via a torque limiter and the separation roller separates the medium with the rotational torque applied to the separation roller.

A recording medium conveyance device includes a storage, a conveyer that conveys a conveyed object, an ultrasonic sensor that outputs a value indicating an attenuation amount of an ultrasonic wave caused by the conveyed object, and a hardware processor. The hardware processor executes a type detection process of detecting a type of the conveyed object based on output of the ultrasonic sensor and storing the type in the storage and an overlay detection process of detecting whether the conveyed object is in an overlay state in which a gap is present based on output of the ultrasonic sensor, and switches to either one of the type detection process and the overlay detection process. The hardware processor executes the type detection process when the type is not stored in the storage and executes the overlay detection process when the type is stored in the storage.