A paper sheet S is intermittently transported by a transport mechanism 6 and each processing unit 7, 8 operates while the transport mechanism pauses the transport operation. An information acquisition unit 9 obtains paper information from the paper sheet. A control unit 10 stores the paper information of the paper sheet to be processed for each processing unit, updates the data of the memory in a manner such that the paper information of the paper sheet associated with the previous processing unit is associated with the next processing unit every time the transport mechanism transports, and configures the settings of each processing unit for the next processing operation based on the paper information every time the processing operation of the processing unit is completed.

A sheet feeding device includes a roller pair being mutually non-separable; and a roller pair being mutually separable. The sheet feeding device temporarily stops a sheet in a registration position of the non-separable roller pair and then resumes feeding the sheet. The sheet feeding device feeds sheets such that a following sheet reaches the registration position from the separable roller pair after completion of ejection of a preceding sheet.

Provided is a recording medium detection device which prevents a recording medium from jamming. The device comprises: a first roller and a second roller which nip and transport a recording medium; a roller shaft which rotatably supports the second roller; a shaft support; and a displacement detector. The shaft support supports the roller shaft movably in the thickness direction of the recording medium. The displacement detector detects displacement of the second roller in the thickness direction. The shaft support further supports the second roller movably in the transportation direction of the recording medium through the roller shaft.

According to one embodiment, a sheet conveying device includes a placement tray, a presence detection sensor, and a control unit. The placement tray places a sheet thereon. The presence detection sensor detects the presence or absence of the sheet on the placement tray. The control unit delays a determination timing of the presence or absence of the sheet placed on the placement tray to a predetermined timing when a condition indicating that the remaining sheets placed on the placement tray are only a few is satisfied.

A recoding medium conveying device includes a conveyance belt, a first sensor, a second sensor, and circuitry. The conveyance belt has an endless loop shape and a length capable of conveying a plurality of recording media in one rotation. The first sensor is disposed upstream from the conveyance belt in a conveyance direction of a recording medium and is configured to detect the recording medium. The second sensor is configured to detect a home position of the conveyance belt. The circuitry is configured to adjust a rotation speed of the conveyance belt, while the conveyance belt makes one rotation, to eliminate an amount of deviation between a first detection timing of the recording medium detected by the first sensor and a second detection timing of the home position of the conveyance belt detected by the second sensor.

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 feeding apparatus includes a stacking portion, a regulating portion, a moving portion, and a detection unit. The regulating portion abuts, in a width direction, one side of stacking portion sheets having different widths and regulates movement of the sheets in the width direction. The detection unit detects a position of the moving portion in an intersecting direction. The regulating portion includes an abut portion. By abutting or not abutting the abut portion, the moving portion moves to a first position and a second position. When the moving portion moves to the first position or the second position in a predetermined proceeding direction, the moving portion does not move from the first position or the second position while the regulating portion takes a position where the regulating portion further moves in the predetermined proceeding direction.

A printing apparatus includes a conveyance unit configured to convey a tray on which a printing medium is placed, a printing unit configured to perform printing on a print surface of a printing medium on the tray based on a print job, and a first detection unit configured to detect a relative position relationship between the tray and a printing medium placed on the tray. In addition, a control unit is configured to control the printing unit not to perform printing in a case where the first detection unit detects that the printing medium is not placed at an appropriate position, and a selecting unit is configured to select whether to continue printing irrespective of results of the detection by the first detection unit.

An image forming apparatus includes first and second light emitting units, a light receiving unit for receiving light of the first light emitting unit when it is reflected, and receiving light of the second light emitting unit when it is not reflected, to output a signal of a predetermined level, and a control unit for starting light emission of the first light emitting unit before a front end of a paper sheet reaches an area, stopping light emission of the first light emitting unit while starting light emission of the second light emitting unit before a rear end of the paper sheet passes the area, and detecting a length of the paper sheet based on time after the output signal becomes a predetermined level during light emission of the first light emitting unit until the output signal becomes the predetermined level during light emission of the second light emitting unit.

An image forming apparatus includes first and second light emitting units, a light receiving unit for receiving light of the first light emitting unit when it is reflected, and receiving light of the second light emitting unit when it is not reflected, to output a signal of a predetermined level, and a control unit for starting light emission of the first light emitting unit before a front end of a paper sheet reaches an area, stopping light emission of the first light emitting unit while starting light emission of the second light emitting unit before a rear end of the paper sheet passes the area, and detecting a length of the paper sheet based on time after the output signal becomes a predetermined level during light emission of the first light emitting unit until the output signal becomes the predetermined level during light emission of the second light emitting unit.