In one embodiment, an image forming apparatus has an image forming device, a discharge port of a recording medium, a conveying device of the recording medium, and a controller. The controller judges a kind of the recording medium and the discharge port that is a conveying destination of the recording medium. The controller controls a conveying speed of the recording medium to be discharged from the discharge port by the conveying device, in accordance with the kind of the recording medium and the conveying destination of the recording medium which have been judged.

In one embodiment, an image forming apparatus has an image forming device, a discharge port of a recording medium, a conveying device of the recording medium, and a controller. The controller judges a kind of the recording medium and the discharge port that is a conveying destination of the recording medium. The controller controls a conveying speed of the recording medium to be discharged from the discharge port by the conveying device, in accordance with the kind of the recording medium and the conveying destination of the recording medium which have been judged.

A print device includes: a first opening via which a print medium is to be inserted or ejected; a second opening via which the print medium is to be ejected; a transport roller that transports the print medium; a housing that contains a transport route; a first sensor that detects presence of the print medium; and a second sensor that detects the presence of the print medium on an upstream side of the first sensor; and a processor. When a command designates the print medium to be ejected to the outside via the second opening and a length of the print medium determined from the detection states of the first and the second sensors is shorter than or equal to a predetermined length, the processor ejects the print medium to the outside via the first opening.

A sheet sorting apparatus includes a first tray detachable from an apparatus main body, a second tray arranged below the first tray, a discharge unit to discharge a sheet to the first or second tray, a tray detecting unit to detect that the first tray is detached from the apparatus main body, a full stack detecting unit to detect a fully stacked condition of the first tray, and a control unit to control the discharge unit. In a case where the tray detecting unit detects that the first tray is detached from the apparatus main body, the control unit controls the discharge unit not to discharge a sheet to the second tray when a number of sheets discharged to the second tray reaches a threshold number of sheets, even though the full stack detecting unit does not detect the fully stacked condition.

A sheet sorting apparatus includes a first tray detachable from an apparatus main body, a second tray arranged below the first tray, a discharge unit to discharge a sheet to the first or second tray, a tray detecting unit to detect that the first tray is detached from the apparatus main body, a full stack detecting unit to detect a fully stacked condition of the first tray, and a control unit to control the discharge unit. In a case where the tray detecting unit detects that the first tray is detached from the apparatus main body, the control unit controls the discharge unit not to discharge a sheet to the second tray when a number of sheets discharged to the second tray reaches a threshold number of sheets, even though the full stack detecting unit does not detect the fully stacked condition.

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 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 decurling device includes a first conveyance path, a second conveyance path, a first switch, a decurler, and a controller. A sheet is conveyed along the first conveyance path or the second conveyance path. The first switch switches a route of conveyance of the sheet to the first conveyance path or the second conveyance path. The sheet has a first main surface and a second main surface. The decurler is located in the second conveyance path. The decurler corrects curl of the sheet. In a situation in which a weight per unit area of the sheet is smaller than a first threshold value, the controller controls the first switch such that the sheet is conveyed along the second conveyance path.

A decurling device includes a first conveyance path, a second conveyance path, a first switch, a decurler, and a controller. A sheet is conveyed along the first conveyance path or the second conveyance path. The first switch switches a route of conveyance of the sheet to the first conveyance path or the second conveyance path. The sheet has a first main surface and a second main surface. The decurler is located in the second conveyance path. The decurler corrects curl of the sheet. In a situation in which a weight per unit area of the sheet is smaller than a first threshold value, the controller controls the first switch such that the sheet is conveyed along the second conveyance path.

A sheet sorting device includes three or more trays including a predetermined tray detachable from an apparatus main body and a tray different from the predetermined tray, a discharge unit to discharge a sheet to any one of the three or more trays, a control unit, and a tray detection unit to detect that the predetermined tray is detached from the apparatus main body. The control unit sets a sheet discharge destination such that a sheet conforming to a preset condition is discharged to the predetermined tray through the discharge unit. Where the tray detection unit detects that the predetermined tray is detached from the apparatus main body, the control unit sets a sheet discharge destination that has been set to the predetermined tray to the tray different from the predetermined tray based on a state of each of the trays other than the detached predetermined tray.