An image-forming apparatus for forming an image on a sheet includes an image-forming unit that forms the image on the sheet, and a conveying unit that conveys the sheet on which the image is formed by the image-forming unit. The conveying unit includes a pair of first rollers that discharges the sheet to the outside of the image-forming apparatus and a pair of second rollers that conveys the sheet in a direction in which the sheet is discharged to the outside of the image-forming apparatus and that subsequently switches a conveyance direction of the sheet to an opposite direction to convey the sheet again to the image-forming unit. The pair of the first rollers and the pair of the second rollers partially overlap when viewed in a width direction of the sheet that is perpendicular to the conveyance direction of the sheet.

In an example, a method includes receiving, by at least one processor, an instruction to print a user specified printing task to at least one media sheet. Print operation instructions may be determined. Such print operation instructions may comprise instructions to control a print apparatus to print user specified printing print apparatus to print the user specified printing task and instructions to control a print apparatus to carry out at least one cleaning operation, wherein the cleaning operation comprises duplex printing a print media sheet.

In an example, a method includes receiving, by at least one processor, an instruction to print a user specified printing task to at least one media sheet. Print operation instructions may be determined. Such print operation instructions may comprise instructions to control a print apparatus to print user specified printing print apparatus to print the user specified printing task and instructions to control a print apparatus to carry out at least one cleaning operation, wherein the cleaning operation comprises duplex printing a print media sheet.

An intelligent advertisement publishing system and method based on a double-sided printer distribution map. The method includes: generating a distribution map based on geographical location information of double-sided printers; displaying the distribution map of the double-sided printers, and after obtaining advertisement content input by a user and an advertisement publishing scope selected by the user on the distribution map, generating advertisement information; parsing to obtain the corresponding advertisement publishing scope and advertisement content, generating corresponding advertisement push information based on the advertisement content, and sending the advertisement push information to double-sided printers in the advertisement publishing scope; and enabling the double-sided printers to print the corresponding advertisement information at the back of cash register paper when printing cash registration information.

A duplex printing method includes, determining an amount of shrinkage of a media sheet onto which a front side image has been printed; scaling an image to be printed on a back side of the sheet with a scaling function that depends upon the determined shrinkage; and printing the scaled image on the back side of the sheet. The step of determining includes predicting a shrinkage of a media sheet on the basis of process parameters, and on the basis of a model that is defined by a set of model parameters and that describes a dependence of the shrinkage on the process parameters, the process parameters including at least an amount of marking material to be applied to the front side of the sheet; measuring an actual shrinkage of the sheet; and adjusting the model parameters based on a comparison between the predicted shrinkage and the measured shrinkage to improve a prediction of a shrinkage for a subsequent sheet.

An image forming apparatus includes an image forming unit configured to form an image on a sheet; a reading unit configured to read the image formed on the sheet by the image forming unit during a period in which the sheet is being conveyed by a conveying unit; a control unit configured to control a conveyance speed of the sheet by the conveying unit; and a determination unit configured to determine whether or not there is an image defect in the image formed on the sheet by the image forming unit based on image data of a first partial image read by the reading unit, excluding a second partial image passing through the reading unit during a speed variation period in which the control unit varies the conveyance speed of the sheet.

A controller is configured to: when an inter-sheet time is shorter than or equal to a first time, maintain a developing roller in contact with a photosensitive drum during an inter-sheet time; when the inter-sheet time is longer than the first time and shorter than or equal to a second time longer than the first time, perform, during the inter-sheet time, at least part of temporary separation processing of temporarily separating the developing roller from the photosensitive drum in a state where the photosensitive drum is rotating; and when the inter-sheet time is longer than the second time, perform, during the inter-sheet time, at least part of temporary stop processing of separating the developing roller from the photosensitive drum and then stopping rotation of the photosensitive drum, and subsequently restarting rotation thereof and then bringing the developing roller into contact with the photosensitive drum.

An image forming apparatus includes an image forming unit configured to form an image on a sheet; a first roller configured to feed a sheet, on one surface of which an image was formed by the image forming unit, to a double-sided conveyance path for forming an image on another surface opposite to the one surface of the sheet; a second roller positioned downstream of the first roller in a conveyance direction of the double-sided conveyance path; a third roller positioned downstream of the second roller in the conveyance direction; a fourth roller positioned downstream of the third roller in the conveyance direction; a first driving unit configured to drive the first roller and the second roller; and a second driving unit configured to drive the third roller and the fourth roller.

An image forming device, includes: a transfer unit that transfers a toner image onto a recording medium being conveyed; a main heating unit that is disposed at a downstream side of the transfer unit in a conveyance direction of the recording medium, heats the recording medium in contact with the recording medium, and fixes the toner image to the recording medium; a reversing unit that reverses front and back of the recording medium having the toner image fixed on a first surface of the recording medium by the main heating unit, and sends the recording medium to the transfer unit; a preheating unit that is arranged between the transfer unit and the main heating unit in the conveyance direction of the recording medium and heats the recording medium in a non-contact state, the preheating unit being configured to heat the recording medium so that, when the recording medium that is sent to the transfer unit by the reversing unit and on which the toner image is transferred to a second surface is heated, a temperature of the first surface of the recording medium is higher than a softening point of a toner before the recording medium is heated by the main heating unit; and a non-contact unit that brings a toner image forming region on the first surface of the recording medium on which the toner image is transferred onto the second surface and a member other than the recording medium between the preheating unit and the main heating unit in a non-contact state.

A transmission unit transmits driving force to be supplied from a motor to a roller pair. A switching unit acts on the transmission unit to switch a rotation direction of the roller pair by the driving force between a normal rotation and a reverse rotation. A control unit controls a rotation speed of the motor to convey the sheet at a second conveyance speed in a part of a first time period. The second conveyance speed is lower than a first conveyance speed. The first conveyance speed is a conveyance speed when the sheet is conveyed in the image forming unit. In the first time period the sheet having the image formed on the first surface is conveyed in a first direction. In a second time period the sheet is conveyed in a second direction.