There is a need to provide an image generator and an image generation method capable of avoiding wasting a normal printed matter if any in sheets of paper output after an occurrence of waste paper. When paper contains an abnormal image, the paper is detected as waste paper based on a read result from an image read sensor. Detection of the waste paper allows an image generator to perform reprint from a print job for the waste paper. Normal-image paper may be contained in sheets of paper output between detection of the waste paper and the reprint to be performed. In this case, the normal-image paper is used as a normal printed matter and is avoided from being consumed wastefully.

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.

There is a need to provide an image generator and an image generation method capable of avoiding wasting a normal printed matter if any in sheets of paper output after an occurrence of waste paper. When paper contains an abnormal image, the paper is detected as waste paper based on a read result from an image read sensor. Detection of the waste paper allows an image generator to perform reprint from a print job for the waste paper. Normal-image paper may be contained in sheets of paper output between detection of the waste paper and the reprint to be performed. In this case, the normal-image paper is used as a normal printed matter and is avoided from being consumed wastefully.

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 sheet conveying apparatus includes a sheet stacking portion, a sheet feeding portion, a sheet conveyance path, an escape conveyance path branching off from the sheet conveyance path at a branch-off portion, a sheet discharge portion, a double-feed detector configured to detect double-feed of the sheet at a detection position, and a controller. A path length in the sheet conveyance path from the detection position to the branch-off portion is shorter than a length of a conveyable sheet. The controller switches a mode between a first mode of discharging the sheet for which the double-feed has been detected onto the sheet discharge portion via the escape conveyance path and a second mode of stopping the sheet for which the double-feed has been detected on the sheet conveyance path without discharging the sheet onto the sheet discharge portion in accordance with timing at which the double-feed detector detects the double-feed.

A transport monitoring control device includes a pair of rollers configured to transport a recording medium while nipping the recording medium therebetween, the pair of rollers having circumferential surfaces coming in contact with the recording medium, the circumferential surfaces being different from each other in hardness, a driving unit configured to drive the pair of rollers, a detector configured to detect waveforms related to a load of the driving unit, an extractor configured to extract a peak waveform having an extreme point temporarily exceeding a predetermined threshold value, from among the waveforms detected by the detector, and a determining unit configured to determine whether multi-feed of the recording medium is present, based on the number of peak waveforms extracted by the extractor.

A multi-feed detection apparatus for detecting multi-feed of a sheet conveyed along a paper path is provided. The apparatus includes a first movement amount sensor disposed on the paper path to face a first surface of the sheet to detect a movement amount of the sheet; a second movement amount sensor disposed, on the paper path, in a position at which the first movement amount sensor is disposed to face a second surface of the sheet to detect a movement amount of the sheet; and a determination portion configured to determine that a conveyance state of the sheet is multi-feed when a difference between the movement amount of the sheet detected by the first movement amount sensor and the movement amount of the sheet detected by the second movement amount sensor is equal to or greater than a threshold.

An image forming apparatus includes a fixing roller to fix an image by heating a sheet on which the image is transferred and to convey the sheet. In a case in which a first plain paper of which a sheet length in a sheet conveyance direction is equal to or more than a predetermined length is conveyed, the fixing roller conveys the first plain paper at a first speed. In a case in which a second plain paper of which the sheet length is less than the predetermined length is conveyed, the fixing roller conveys the second plain paper at a second speed less than the first speed. In a case in which an envelope of which the sheet length is less than the predetermined length is conveyed, the fixing roller conveys the second envelope at the first speed.

An image forming apparatus includes a paper feed unit that includes a paper feed contact portion which comes into contact with the recording material stored in a storage unit, and that feeds the recording material in contact with the paper feed contact portion. The image forming apparatus further includes a separation unit provided downstream of the paper feed unit in a conveyance direction of the recording material, and that includes a separation contact portion which comes into contact with the fed recording material. In a case where information based on a result of detecting the recording material being conveyed indicates that a plurality of recording materials are simultaneously positioned in a notification section, An information processing apparatus gives notification such that a display apparatus displays information regarding that the plurality of recording materials are present in the notification section.