In an image forming apparatus, a controller performs processes in accordance with an operation mode settable to one of a first subscription mode and a second subscription mode. The first subscription mode corresponds to a first subscription in which a specific-color cartridge is a subscription subject and a non-specific-color cartridge is not the subscription subject. The second subscription mode corresponds to a second subscription in which both the specific-color cartridge and the non-specific-color cartridge are the subscription subject. The controller performs restricting usage of the non-specific-color cartridge in a case where the first subscription mode is set as the operation mode and the type information of the non-specific-color cartridge indicates the subscription type, compared to a case where the second subscription mode is set as the operation mode and the type information of the non-specific-color cartridge indicates the subscription type.

A white toner includes a toner particle that contains a binder resin containing a hybrid resin in which an amorphous resin unit and a crystalline polyester resin unit are chemically bonded to each other, surface-treated titanium oxide, and a release agent, in which a proportion of Al atoms in a surface of the surface-treated titanium oxide is 3 atomic % or greater and 20 atomic % or less, and a proportion of Ti atoms in the surface is 5 atomic % or greater and 15 atomic % or less.

A transfer member includes: an inner layer; an outer layer provided on an outer periphery of the inner layer; and a surface layer provided on an outer periphery of the outer layer, both end portions of the surface layer in circumferential directions extending in the circumferential directions from both end portions of the outer layer in the circumferential directions.

A belt driving device includes an adjustment roller to stretch and rotate an endless belt; an inclination adjuster including a cam to adjust inclination of the roller to control deviation of the belt; a belt position detector to detect a belt position in a direction orthogonal to a movement direction of the belt; a stepping motor to rotate the cam; and a control output adjuster to adjust a control output to be supplied to the motor based on the belt position. When obtaining a rotation angle less than one step of the motor, the control output adjuster supplies the control output to the motor for a time corresponding to the rotation angle less than the one step out of a supply time of the control output for obtaining a rotation angle of the one step, and stops supplying the control output for a remaining time out of the supply time.

An image forming apparatus configured to perform high-quality image formation regardless of an accuracy of mounting surface emitting element array chips includes an image data generating portion configured to generate pixel data equivalent to 2,400 dpi; a joint correcting portion configured to correct a misregistration amount at a joint between a predetermined surface emitting element array chip and a surface emitting element array chip arranged adjacent to the predetermined surface emitting element array chip; and a resolution converting portion configured to convert a resolution of the pixel data from 2,400 dpi to 1,200 dpi. The joint correcting portion is configured to correct the misregistration amount at the joint with respect to pixel data obtained after the resolution thereof is converted by the resolution converting portion.

An image forming apparatus configured to perform high-quality image formation regardless of an accuracy of mounting surface emitting element array chips includes an image data generating portion configured to generate pixel data equivalent to 2,400 dpi; a joint correcting portion configured to correct a misregistration amount at a joint between a predetermined surface emitting element array chip and a surface emitting element array chip arranged adjacent to the predetermined surface emitting element array chip; and a resolution converting portion configured to convert a resolution of the pixel data from 2,400 dpi to 1,200 dpi. The joint correcting portion is configured to correct the misregistration amount at the joint with respect to pixel data obtained after the resolution thereof is converted by the resolution converting portion.

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 forms a color image on a recording medium by superimposing images of colors formed by image forming units. The apparatus includes a processor that: acquires a read image by reading the recording medium on which the color image has been formed; forms a register patch outside a job image forming region of the recording medium; and corrects image forming positions of the image forming units based on the read image that includes the register patch. The register patch includes: a leading end patch and a rear end patch formed with a reference color material; and one or more measurement target color patches formed with measurement target color materials between the leading end patch and the rear end patch. The hardware processor corrects the image forming positions based on relative positions of the leading end patch, the rear end patch, and the measurement target color patches.

An image forming apparatus forms a color image on a recording medium by superimposing images of colors formed by image forming units. The apparatus includes a processor that: acquires a read image by reading the recording medium on which the color image has been formed; forms a register patch outside a job image forming region of the recording medium; and corrects image forming positions of the image forming units based on the read image that includes the register patch. The register patch includes: a leading end patch and a rear end patch formed with a reference color material; and one or more measurement target color patches formed with measurement target color materials between the leading end patch and the rear end patch. The hardware processor corrects the image forming positions based on relative positions of the leading end patch, the rear end patch, and the measurement target color patches.

An image forming apparatus includes plural image forming units and a controller. The plural image forming units are configured to form images of colors using colorants, respectively. The controller is configured to perform control such that the plural images formed by the plural image forming units are output as one image onto a recording medium. At least two of the image forming units are configured to form images using colorants of special colors, respectively and are arranged in succession.