An image forming system comprises a sheet supply section configured to supply a sheet for printing. The system includes a registration roller configured to guide the sheet supplied from the sheet supply section along a conveyance path. A first image forming section is configured to form a first image on the sheet based on reference image information using a first colorant type that is capable of being fixed to the sheet by heat. A fixing section is configured to heat the sheet on which the first image has been formed. A second image forming section is configured to receive the sheet from the fixing section and form a second image using a second colorant type on the sheet after the sheet has been passed through the fixing section. A controller is configured to control a heating temperature of the fixing section in two or more stages.

An image forming apparatus determines whether crease processing at a plurality of portions set on the sheet includes crease processing on two, front and back surfaces of the sheet; determines, if it is determined that crease processing includes crease processing on the two surfaces of the sheet, whether a connected post-processing apparatus that performs crease processing on a sheet can perform crease processing on the two, front and back surfaces of the sheet by one feeding; and controls, if it is determined that the connected post-processing apparatus cannot perform crease processing on the two surfaces by one feeding, to change, to one of the front and back surfaces of the sheet based on attribute information of the sheet, a surface to be processed in crease processing at the plurality of portions.

System and method for adaptively switching a print mode from duplex to simplex. In one embodiment, a processor monitors memory to detect a duplex page followed by multiple contiguous simplex pages. The processor estimates a first time for the duplex sheet corresponding to the duplex page to traverse a duplex media path for switching from a duplex print mode to a simplex print mode. The processor also estimates a second time for simplex sheets corresponding to the multiple contiguous simplex pages to traverse the simplex media path in the simplex print mode, and estimates a third time for the simplex sheets to traverse the duplex media path in the duplex print mode. If the third time is less than a sum of the first time and the second time, the processor modifies the instructions to print the multiple contiguous simplex pages in the duplex print mode.

An image forming apparatus is connected to a paper processing apparatus and includes an image forming unit, a nip part and a hardware processor. The image forming unit performs image forming on continuous paper being conveyed on a conveyance path. The nip part nips the paper on the conveyance path. The processor selectively performs first control and second control according to an output timing of a conveyance control signal if the signal is output from the paper processing apparatus or the image forming apparatus. In the first control, the processor notifies the paper processing apparatus of permission to start or stop conveying the paper after causing the nip part to perform a press-and-contact operation or a separation operation. In the second control, the processor notifies the paper processing apparatus of the permission without causing the nip part to perform either operation.

An image forming system of an aspect of the present invention includes: a first image forming portion; a second image forming portion connected in series to the first image forming portion; and an assignment determining portion that determines an assignment of image formation of print data to the first image forming portion and the second image forming portion in accordance with contents of the print data. The first image forming portion forms a first image on the continuous sheet on the basis of the assignment determined by the assignment determining portion, and the second image forming portion forms a second image on a region which is different from a region where the first image is formed on the continuous sheet and which overlaps a non-printable region that is a region where the first image forming portion cannot print, on the basis of the assignment determined by the assignment determining portion.

A series-connected tandem image forming system includes first and second image forming apparatuses capable of forming images on recording media by image forming units, the first and second image forming apparatuses being connected in series, the image forming system forming an image on a recording media by either one or both of the first and second image forming apparatuses, wherein the first image forming apparatus includes a first conveyance path for conveyance of the recording medium, and a second conveyance path for conveyance of the recording medium, the first and second conveyance paths being selectable therebetween, the second image forming apparatus includes a third conveyance path for conveyance of the recording medium, and a fourth conveyance path for conveyance of the recording medium, the third and fourth conveyance paths being selectable therebetween.

A image forming system of the present inventation includes a control section that causes a pattern image for image density control to be formed on an image carrier, and performs density correction control for correcting a density of a formed image on the basis of density information on the formed pattern image for image density control, wherein the control section determines a timing for performing the density correction control, on the basis of information corresponding to a density difference generated between images formed by the plurality of image forming apparatuses.

An image formation system includes a cooling section that cools a sheet in a period after a toner image is fixed on a first surface by a first fixing section and before the toner image is formed on a second surface of the sheet by a second image forming apparatus, and a hardware processor that controls a cooling operation of the cooling section in accordance with a parameter representing a temperature of an image forming section of the second image forming apparatus.

An image forming system which suppresses the decline in printing speed without user intervention when the speed of data transmission to a storage does not meet an allowable speed, and a control method for the system. A first acquisition part acquires the speed of data transmission to the storage of each of plural image forming apparatuses and a second acquisition part acquires the data transmission speed between image forming apparatuses. When the speed of data transmission to a given image forming apparatus among the apparatuses is lower than a specified value, if the speed of data transmission to the storage of another image forming apparatus and the data transmission speed between image forming apparatuses are both higher than a given value, a striping part performs striping to distribute and store data into the storage of the given image forming apparatus and the storage of the other image forming apparatus.

A sheet characteristic detection system that detects a sheet characteristic, includes: a sheet characteristic detection device that includes a plurality of media sensors corresponding to a plurality of different sheet characteristics; and a hardware processor that is capable of changing a type of the sheet characteristic to be detected by the plurality of media sensors.