To provide an image forming apparatus capable of achieving both correction accuracy of skew correction and minimization of a margin between images.

A color shift amount calculator that calculates a color shift amount, and a first skew correction controller and a second skew correction controller that control skew correction of color shift are included. The first skew correction controller controls first skew correction by a mechanical operation by the image former on the basis of a first color shift residual target value set in advance. The second skew correction controller controls second skew correction, by image processing, of the color shift after the control by the first skew correction controller on the basis of a second color shift residual target value set in advance.

A disclosed fixing device includes a pressing member; an endless tubular fixing member disposed opposite to the pressing member; a heating source configured to heat the fixing member; a nip forming member disposed opposite to the pressing member via the fixing member to form a nip portion; and a supply unit configured to supply lubricant to a portion of an inner surface of the fixing member, the portion facing the nip forming member, wherein the nip forming member includes a contact portion that contacts the inner surface of the fixing member, the contact portion includes a guide portion for guiding lubricant, and the guide portion is formed by extending obliquely from opposite ends in a width direction toward a center of the fixing member as the contact portion moves from upstream to downstream in a rotational direction of the fixing member.

To provide an image forming apparatus capable of achieving both correction accuracy of skew correction and minimization of a margin between images. A color shift amount calculator that calculates a color shift amount, and a first skew correction controller and a second skew correction controller that control skew correction of color shift are included. The first skew correction controller controls first skew correction by a mechanical operation by the image former on the basis of a first color shift residual target value set in advance. The second skew correction controller controls second skew correction, by image processing, of the color shift after the control by the first skew correction controller on the basis of a second color shift residual target value set in advance.

An image forming apparatus includes a fixing device, and a controller. The controller acts as a print controller, a drawing controller, and an engine controller. The print controller receives a printing request. The drawing controller identifies an image to be drawn, through image processing of a page image designated by the printing request with respect to each page, and identifies a use amount of toner required for the image to be drawn. The engine controller executes a primary fixing temperature control including controlling the fixing temperature according to color information designated by the printing request with respect to each page, and executes, after executing the primary fixing temperature control, a secondary fixing temperature control including controlling the fixing temperature according to the use amount of toner identified by the drawing controller.

An image forming apparatus includes a fixing device, and a controller. The controller acts as a print controller, a drawing controller, and an engine controller. The print controller receives a printing request. The drawing controller identifies an image to be drawn, through image processing of a page image designated by the printing request with respect to each page, and identifies a use amount of toner required for the image to be drawn. The engine controller executes a primary fixing temperature control including controlling the fixing temperature according to color information designated by the printing request with respect to each page, and executes, after executing the primary fixing temperature control, a secondary fixing temperature control including controlling the fixing temperature according to the use amount of toner identified by the drawing controller.

In an image-forming apparatus, a controller is configured to perform: in a case where the controller performs forming a multicolor image on a sheet: bringing, in response to a temperature of a fixing device reaching a first temperature lower than a fixing temperature, first and second developing rollers into contact with first and second photosensitive drums; and feeding, after a first period of time elapses from a time when the temperature of the fixing device reaches the first temperature, a sheet from a sheet tray toward the belt using a pickup roller. The controller is configured to further perform: in a case where the controller performs forming a single-color image on the sheet: bringing, after a second period of time elapses from the time when the temperature of the fixing device reaches the first temperature, the second developing roller into contact with the second photosensitive drum; and the feeding.

An image forming apparatus includes an image forming unit, a fixing unit, an image analyzer, and a temperature controller configured to control a temperature of the fixing unit in accordance to a target temperature. The image analyzer is configured to analyze image data for forming the toner image by the image forming unit, to evaluate a continuity of pixels of an image contained in the image data. The temperature controller is configured to change the target temperature based on analysis results of the image analyzer such that a value of the target temperature in a case where the image data contains an image with a continuity of pixels equal to or smaller than a predetermined value is higher than a value of the target temperature in a case where the image data contains no image with a continuity of pixels equal to or smaller than the predetermined value.

An image forming apparatus includes an image forming unit, a fixing unit, an image analyzer, and a temperature controller configured to control a temperature of the fixing unit in accordance to a target temperature. The image analyzer is configured to analyze image data for forming the toner image by the image forming unit, to evaluate a continuity of pixels of an image contained in the image data. The temperature controller is configured to change the target temperature based on analysis results of the image analyzer such that a value of the target temperature in a case where the image data contains an image with a continuity of pixels equal to or smaller than a predetermined value is higher than a value of the target temperature in a case where the image data contains no image with a continuity of pixels equal to or smaller than the predetermined value.

A disclosed fixing device includes a pressing member; an endless tubular fixing member disposed opposite to the pressing member; a heating source configured to heat the fixing member; a nip forming member disposed opposite to the pressing member via the fixing member to form a nip portion; and a supply unit configured to supply lubricant to a portion of an inner surface of the fixing member, the portion facing the nip forming member, wherein the nip forming member includes a contact portion that contacts the inner surface of the fixing member, the contact portion includes a guide portion for guiding lubricant, and the guide portion is formed by extending obliquely from opposite ends in a width direction toward a center of the fixing member as the contact portion moves from upstream to downstream in a rotational direction of the fixing member.

An image forming system includes an image forming unit including a first photosensitive member, a first developing unit, a second photosensitive member, a second developing unit, a third photosensitive member, a third developing unit, a fourth photosensitive member, and a fourth developing unit, a varnish applying unit; an irradiation unit; and a controller configured to control image formation by the image forming unit to form a black image, on which the varnish is superimposed, with the yellow toner, the magenta toner, and the cyan toner.