An image forming system includes an image forming apparatus and a post-processing device. The image forming apparatus includes a scanner reading image data from a sheet, an image forming part forming an image on the sheet, and a sheet ejecting part ejecting the sheet after forming the image. The post-processing device includes a post-processing conveying path, and a stapling part. The post-processing conveying path introduces the sheet from the sheet ejecting part and conveys the sheet. The stapling part collects sheets conveyed on the post-processing conveying path for each predetermined number of sheets and executes staple processing to the sheets. The image forming apparatus or the post-processing device includes a size deciding part deciding a sheet size based on the image data. The post-processing device includes a staple controlling part determining a binding position for the staple processing on the basis of the sheet size.

An image forming apparatus includes an image forming unit and a reading unit. The image forming unit is configured to form an image. The reading unit has a first reading mode, in which a document conveyed by a conveyance unit is read, and a second reading mode, in which a document placed on a platen glass is read. A first correction mode, in which correction data is generated using a result of reading the test document in the first reading mode, or a second correction mode, in which correction data is generated using a result of reading the test document in the second reading mode, is executed based on a result of detection of placement of a test document on the reading unit.

An image forming device includes a transfer unit that transfers a toner image onto a recording medium that has first and second surfaces and is conveyed in a conveyance direction; a main heating unit arranged downstream of the transfer unit in the conveyance direction, and which contacts and heats the recording medium and fixes the toner image onto the recording medium; a reversing unit that reverses front and back of the recording medium having a first toner image fixed onto the first surface; and a preheating unit arranged between the transfer and main heating units in the conveyance direction and that heats the recording medium having a second toner image transferred onto the second surface. The preheating unit heats the recording medium so that a temperature of the first surface is lower than a softening point of a toner before the recording medium is heated by the main heating unit.

An image forming apparatus includes an image forming section, a detector, and a display section. The image forming section forms an image on a first side of a sheet. The sheet has the first side and a second side. The detector is positioned upstream of the image forming section in a sheet conveyance direction. The detector detects whether or not an image has been formed on the first side of the sheet. The display section displays information indicating that an image has been formed on the first side of the sheet when the detector detects that an image has been formed on the first side of the sheet.

A transport apparatus includes: a transport mechanism that transports a medium manually inserted; and a control unit that changes, depending on a type of the medium, a start timing of transporting the medium.

A sheet conveying device can selectively execute a first conveyance process of conveying sheets on a first tray and discharging the sheets onto a second tray, a second conveyance process of conveying the sheets on the first tray and discharging the sheets onto a third tray, or a third conveyance process of conveying the sheets on the third tray and discharging the sheets onto the second tray. A control device records conveyance history information indicating by which conveyance processes each of the sheets on the first tray has been conveyed in a storage device. Furthermore, the control device causes the sheet conveying device to sequentially select the first conveyance process or the third conveyance process for each of the sheets based on the conveyance history information and execute the selected process.

An image forming apparatus includes an image forming unit and a reading unit. The image forming unit is configured to form an image. The reading unit has a first reading mode, in which a document conveyed by a conveyance unit is read, and a second reading mode, in which a document placed on a platen glass is read. A first correction mode, in which correction data is generated using a result of reading the test document in the first reading mode, or a second correction mode, in which correction data is generated using a result of reading the test document in the second reading mode, is executed based on a result of detection of placement of a test document on the reading unit.

A document transport device includes a placement portion, a slide member, a movable piece, and a detector. A document is to be placed on the placement portion. The slide member includes a document guide that contacts one lateral side of the document which is placed on the placement portion. The movable piece is provided to the slide member, and includes a shading pattern composed of plural patches that have plural densities corresponding to plural document sizes and having plural adjacent patch density differences that are different from each other. The detector detects a density of the shading pattern, and outputs an output signal for document size recognition.

An image forming apparatus includes a conveyer that conveys a recording medium supporting an image; a softener that softens the image; and a powder applicator that applies powder to the surface of the softened image, in which the applied powder adheres to a range that is narrower in a width direction orthogonal to a conveyance direction of the recording medium conveyed by the conveyer than a maximum width of the image to be supported by the recording medium.

An image forming apparatus includes: an image forming unit configured to form an image on a sheet based on original image data; a selection unit configured to determine a non-image region of the sheet to which toner does not attach in a formation of the image by the image forming unit based on the original image data, and select, from the non-image region, a determination region depending on an image defect to be detected; a reading unit configured to read a surface of the sheet; and a control unit configured to obtain read image data by causing the reading unit to read the determination region after the image forming unit has formed the image, and perform detection processing for detecting whether the image defect has occurred based on the read image data.