A conveying mechanism has a pair of nipping members configured to nip a sheet from both sides thereof at a nipping position and to convey the sheet from upstream to downstream side. The pair of nipping members includes a conveying roller. A controller performs: a motor controlling process of controlling the motor to perform a conveying operation of the sheet by rotation of the conveying roller; a reaction-force calculating process of calculating a reaction-force inference value which corresponds to reaction force that acts on the motor, by removing a friction component generated due to rotation of the motor from a disturbance inference value, the disturbance inference value being calculated from both a control input to the motor and a control output relative to the control input; and a warning process of outputting warning in response to occurrence of multiple feeding of the sheet, based on the reaction-force inference value.

Provided is a transport device including a transport unit that transports a recording medium by interposing the recording medium, a driving unit that drives the transport unit, a detection unit that detects a peak value of a load of the driving unit when the recording medium is discharged from the transport unit, and a derivation unit that derives a thickness of the recording medium based on the peak value detected by the detection unit.

Provided is a paper transporting device and the like capable of suppressing errors in determining jam occurrences. A paper transporting device has: a transport mechanism; an audio signal output unit that outputs an audio signal according to the sound generated during paper transport; an audio jam determination unit that determines, on the basis of the audio signal, whether a jam has occurred; and a control unit that stops paper transport when the audio jam determination unit determines that a jam has occurred. The control unit controls, in the case of card stock or paperboard being transported by the transport mechanism, so that the audio jam determination unit determines whether a jam has occurred at predetermined times using a determination method that is different than the method at other times or so that the audio jam determination unit does not determine whether a jam has occurred.

A sheet conveying device includes: a sending unit configured to send an ultrasonic wave; a receiving unit positioned to face the sending unit across a conveyance path, along which a sheet is conveyed, and configured to receive a first ultrasonic wave, the first ultrasonic wave being an ultrasonic wave sent from the sending unit and passed through the sheet, and output a first voltage corresponding to the first ultrasonic wave; an adjusting unit configured to adjust the first voltage into an adjusted first voltage according to a setting; an amplification unit configured to amplify the adjusted first voltage by a preset amplification factor for multi-feed determination into an amplified first voltage; and a determining unit configured to determine whether or not multi-feed of the sheet has occurred based on the amplified first voltage.

A method for detecting overlapped bank notes is provided. The method includes: step 10, collecting original image data of bank notes; step 20, performing security thread positioning detection on the original image data of the bank notes, to obtain security thread detection data; step 40, determining whether the security thread detection data meets a preset security thread reference condition, going to step 60 if the security thread detection data meets the preset security thread reference condition, and going to step 70 if the security thread detection data does not meet the preset security thread reference condition; step 60, obtaining a determination result that the bank notes are not overlapped, and ending the method; and step 70, obtaining a determining result that the bank notes are overlapped, and ending the method.

A print device includes a supply unit, a print unit, a conveyer, a tensioner, a drive unit, a processor, a medium detector, and a memory. The tensioner is configured to apply tension to the medium. The memory stores computer-readable instructions that, when executed by the processor, instruct the processor to perform processes including correction processing, which is repeated a plurality of times, of controlling the drive unit and applying the tension to the medium by the tensioner during a back-and-forth conveyance operation of conveying the medium in the return direction after conveying the medium in the conveyance direction, and detection processing of detecting attributes of the medium, based on the detection result output from the medium detector, during one of the back-and-forth conveyance operations, of the plurality of back-and-forth conveyance operations.

A print device includes a supply unit, a print unit, a conveyer, a tensioner, a drive unit, a processor, a medium detector, and a memory. The tensioner is configured to apply tension to the medium. The memory stores computer-readable instructions that, when executed by the processor, instruct the processor to perform processes including correction processing, which is repeated a plurality of times, of controlling the drive unit and applying the tension to the medium by the tensioner during a back-and-forth conveyance operation of conveying the medium in the return direction after conveying the medium in the conveyance direction, and detection processing of detecting attributes of the medium, based on the detection result output from the medium detector, during one of the back-and-forth conveyance operations, of the plurality of back-and-forth conveyance operations.

An image reading device includes: a transport unit configured to transport a medium; an emission unit configured to emit an ultrasonic wave in accordance with a driving voltage and a reception unit configured to receive the ultrasonic wave, the emission unit and the reception unit being disposed so that a transport path for the medium transported by the transport unit is interposed therebetween; a reading unit configured to read the medium; and a control unit configured to detect presence or absence of multi-feed of the medium on the basis of a signal received by the reception unit. The image reading device is configured to switch a posture into any of a first posture or a second posture. The first posture is a posture in which the transport path is sloped relative to a mounting surface. The second posture is a posture in which an angle of the transport path relative to the mounting surface is smaller than that in the first posture. The control unit sets a first driving voltage as the driving voltage when the posture is the first posture, and sets a second driving voltage lower than the first driving voltage as the driving voltage when the posture is the second posture.

A conveyance control device controls conveyance of a plurality of sheets including an image-formed sheet. The conveyance control device includes an obtaining unit configured to obtain display image data indicating a display image of each of the plurality of sheets; a region-specifying unit configured to specify common color regions having a common display color on the plurality of sheets based on the display image data; and a multiple feed detector configured to detect multiple feed of the sheets based on a light-receiving amount of light irradiated onto the common color regions; wherein the display image data indicating a display image of the image-formed sheet includes predetermined image data indicating a predetermined image to be previously formed and sheet image data indicating a sheet image displayed in a sheet color of the sheet.

A sheet feeding apparatus is provided with a pick-up roller that contacts sheets loaded on a load tray to pick up, a paper feed roller that feeds a picked-up sheet, and a separation roller brought into press-contact with the paper feed roller to separate the sheet, where the sheets are separated from the pick-up roller, the separation roller is rotated in a sheet return direction different from a sheet feed direction, and subsequently, the paper feed roller is separated from the separation roller. It is possible to prevent damage to a sheet and sheet jam from occurring in pulling out the load tray loaded with sheets to the front side.