A preheating device includes two first inverting members disposed at different positions while obliquely intersecting a feeding direction of a continuous recording medium on which an unfixed image is formed, the first inverting members inverting the recording medium by passing a back surface of the recording medium, on which the unfixed image is not formed, therealong before a fixing operation, and at least one heating rotating body disposed at a position further on an outside than a side edge portion of the recording medium in the feeding direction to preheat the recording medium before the fixing operation by passing a portion of the back surface of the recording medium present between the two first inverting members so that the portion of the back surface is wound around the heating rotating body.

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.

An image forming device continuously forming an image according to a job in a conveying direction of along continuous paper includes: an image formation section forming the image according to the job on the continuous paper; an interval setting section setting a job interval of the image according to the job, which is continuously formed by the image formation section, on the basis of an operation from a user; an image forming process switching section switching two states of a state where the image formation section forms a color image and a state where the image formation section forms a monochromic image; and a switching determination section determining whether or not the two states are switched on the basis of a comparison result between the job interval set by the interval setting section and a paper conveying distance according to a switching time required for switching the two states.

An image forming apparatus that forms an image on a long paper sheet conveyed along a conveyance path extending from a paper feeding side to a paper discharging side includes: an image forming unit configured to transfer a toner image onto the long paper sheet; a fixing unit configured to fix the toner image onto the long paper sheet; a paper existence determining unit configured to determine whether the long paper sheet exists along the conveyance path; a temperature determining unit configured to determine whether a fixing temperature of the fixing unit is equal to or lower than a predetermined temperature when the paper existence determining unit determines that the long paper sheet exists along the conveyance path; and a state setting unit configured to disable a fixing operation of the fixing unit when the temperature determining unit determines that the fixing temperature is higher than the predetermined temperature.

An image forming device is provided. The image forming device includes: a conveyance unit that conveys a continuous paper, an image forming unit that forms an image on a continuous paper conveyed by the conveyance unit, a job selection unit that selects a job to be executed, and a processor that calculates an image forming distance and indicates the calculated image forming distance on a display. The image forming distance is a length in a conveyance direction of the continuous paper needed to execute the selected job.

An image forming apparatus includes: an image forming portion that includes a developing portion configured to supply toner to an image bearing member bearing an electrostatic latent image formed thereon to develop the electrostatic latent image as a toner image, and is configured to form a toner image on a long paper sheet; a notification portion configured to notify a user about information; and a control portion configured to calculate, in accordance with coverage of a toner image that is a target of image formation, a toner image formation distance with which successive image formation is possible without forcibly discharging degraded toner from the developing portion, and to control the notification portion to notify the calculated toner image formation distance as a first toner image formation distance.

A medium carrying device includes a carrying part that carries a continuous print medium, a detection part that includes a light emitting part and a light receiving part arranged sandwiching a carrying path, and that detects the print medium carried on the carrying path according to a light amount that is received by the light receiving part, and a control part that controls operations of the carrying part and the detection part, wherein the control part sets a first emitted light amount of the emitted light of the light emitting part used in image formation to the print medium by performing a light amount measurement using the light emitting part and the light receiving part in a state where the print medium is carried to a first position, and sets a threshold light amount that is used in detecting a boundary position between the first region and the second region by the detection part through performing another light amount measurement by obtaining a receiving light amount of the light receiving part with the first emitted light amount and by determining the threshold light amount based on the receiving light amount in a state where the print medium is carried from the first position to another second position.

An image forming apparatus may comprise the following elements. A stacking unit in which a sheet is stacked. A conveyance unit conveys the sheet. A time-counting unit counts a conveyance time from when the conveyance unit starts to convey the sheet until the sheet arrives at a predetermined position on a conveyance path. A determination unit determines that over stacking has occurred, if the conveyance time of the sheet exceeds a first over stacking threshold value.

An image forming apparatus include a transport unit, a tension adjusting unit, a transfer unit, a fixing unit, and a controller. The transport unit transports continuous paper. The tension adjusting unit adjusts tension of the continuous paper being transported by the transport unit. The transfer unit transfers an image to the continuous paper transported by the transport unit. The fixing unit fixes the image transferred by the transfer unit onto the continuous paper. The controller controls, in a case where the fixing unit is driven in a state in which the fixing unit is separated from the continuous paper and a difference between a transport speed of the transport unit and a fixing speed of the fixing unit has reached a predetermined range, the fixing unit to be in press-contact with the continuous paper.

An image forming apparatus includes: an image forming section configured to form a toner image on a sheet having a paste component; and an end pressing section provided on an upstream side of the image forming section in a sheet conveyance direction, and configured to exert a pressure on an end portion of the sheet while moving from a center toward an end of the sheet in a sheet width direction orthogonal to the sheet conveyance direction.