Examples of a system and method for identifying double feed documents are generally described. A method may include scanning a plurality of documents using a scanner in a first configuration and rejecting identified potential double feeds of checks from the plurality of checks in the first configuration. The method may include rescanning identified potential double feeds in a second configuration.

A medium conveying apparatus includes a conveying roller to convey a medium, a width detection sensor for detecting a width of the medium conveyed by the conveying roller in a direction perpendicular to a conveying direction, an overlap detection sensor for detecting an overlap of the medium conveyed by the conveying roller, and a processor to determine whether to execute an abnormality processing for a multi-feed, based on the width of the medium acquired based on a detection result by the width detection sensor and a detection result by the overlap detection sensor. The processor acquires an overlap detection width being a width in which the medium is estimated to overlap in the direction perpendicular to the conveying direction, based on the detection result by the overlap detection sensor. The processor executes the abnormality processing when the width of the medium and the overlap detection width are equal.

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 medium conveying apparatus includes a conveying roller to convey a medium, an end detection sensor for detecting a position of an end of the medium conveyed by the conveying roller, an overlap detection sensor for detecting an overlap of the medium conveyed by the conveying roller in a detection area, and a processor to determine whether an overlap detection is valid or invalid based on a positional relationship between the position of the end of the medium detected by the end detection sensor and the detection area, and execute an abnormality processing for multi-feed based on a detection result by the overlap detection sensor when it is determined that the overlap detection is valid.

A sheet feeder includes a controller configured to control an emitter to emit an ultrasonic wave toward a target sheet being fed along a sheet guide, control a measurer to measure a first reception intensity of a first component of the ultrasonic wave received by a receiver during a first period of time, control the measurer to measure a second reception intensity of a second component of the ultrasonic wave received by the receiver during a second period of time, and determine a feeding state of the target sheet in a detectable area between the emitter and the receiver within the sheet guide, based on the first reception intensity and the second reception intensity.

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.

Provided is a conveyance apparatus capable of detecting the presence or absence of multi feeding with high accuracy even when a received waveform varies due to a noise from the circuit and an influence due to vibrations being fixedly generated noise components. The conveyance apparatus includes: an original conveying motor configured to convey an original; an ultrasonic transmitter, which is arranged at one of positions sandwiching a conveyance path along which the original is conveyed, and transmits an ultrasonic wave toward the conveyance path; and an ultrasonic receiver, which is arranged at the other one of the positions sandwiching the conveyance path, and receives the ultrasonic wave transmitted from the ultrasonic transmitter. The conveyance apparatus compares a received wave amplitude exhibited with sheet-presence against a threshold value determined based on a received wave amplitude exhibited with sheet-absence to determine whether the original is conveyed by the multi feeding.

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 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 transmitter transmits ultrasound to the conveyance path. A receiver receives the ultrasound. A double-feed detector detects whether or not double-feed of a plurality of sheets has occurred. A controller causes the transmitter to transmit ultrasound at a first burst interval when determining the threshold value, and causes the transmitter to transmit ultrasound at a second burst interval, which is shorter than the first burst interval, when detecting the double-feed of sheets. A double-feed detector determines a threshold value that enables distinction between double-feed and single-feed.