An image forming apparatus includes an image bearer and a primary transferor to be applied with a primary transfer voltage. The primary transferor is disposed opposite the image bearer via an intermediate transferor to form a primary transfer portion where the primary transferor transfers a toner image formed on the image bearer onto the intermediate transferor. A primary transfer electric current detector detects an electric current value of an electric current supplied to the primary transferor. A control-input device receives intermediate transferor replacement data that indicates that the intermediate transferor is replaced. A controller performs a primary transfer voltage determination control that determines the primary transfer voltage based on the detected electric current value and performs the primary transfer voltage determination control at a time when the control-input device receives the intermediate transferor replacement data and a time after an initial image formation after the intermediate transferor is replaced.

An image forming apparatus includes an image bearing member, an image forming portion, a transfer member, a power source, an acquiring portion, and a controller capable of executing an operation in an adjustment mode. A plurality of test toner images transferred onto a recording material in the occurrence in the adjusting mode include a first test toner image transferred under application of a first test voltage and a second test toner image transferred under application of a second test voltage different from the first test voltage. In the operation in the adjustment mode, the controller adjusts the transfer voltage set for transfer on the basis of first information on variation in image density acquired in different regions of the first test toner image and second information on variation in image density acquired in different regions of the second test toner image.

An image forming apparatus includes: an image bearer to adhere toner on a surface of the image bearer to form a toner image of the image bearer according to image data in printing job data; a detector to detect an amount of the toner adhered on the surface of the image bearer; circuitry configured to: determine an adjustment operation to adjust an image formation condition to form the toner image on the image bearer based on job information in the printing job data; perform the adjustment operation to adjust the image formation condition based on the amount of toner detected by the detector; and exclude a predetermined operation from the adjustment operation when the job information satisfies a predetermined condition.

The image forming apparatus includes an image carrier, a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning blade, and a controller. The controller detects printing-coverage rates on a basis of plural areas divided in the longitudinal direction of the image carrier. At a specified timing, the controller executes aging process in which the image carrier in a charged state is driven into rotation under light irradiation by the exposure unit. For the aging process, the controller sets a condition that a light quantity of the exposure unit for an area of larger coverage rate is larger than a light quantity of the exposure unit for an area of smaller coverage rate.

An image printed using toner is optically scanned. Whether the toner is authorized is determined by one or multiple of the following. A toner scatter pattern can be identified within the scanned image and whether the identified toner scatter pattern conforms to expected toner scatter patterns associated with authorized toner can be determined. A color within the scanned image can be identified and whether the identified color conforms to an expected corresponding color associated with the authorized toner can be determined. An image artifact within the scanned image associated with failure of a cartridge in which the toner is installed can be identified and whether the image artifact conforms to expected image artifacts associated with failure of an authorized cartridge in which the authorized toner is installed can be determined.

An image forming apparatus is configured to, based on a reading result of a test image, generate data that is used to adjust image forming positions of toner images to be formed by an image forming unit, control an image forming position of a first toner image to be formed by the image forming unit in a first contact state based on first data, the first toner image being transferred to a first sheet, and control an image forming position of a second toner image to be formed by the image forming unit in a second contact state based on second data that is different from the first data, the second toner image being transferred to a second sheet, wherein a type of the second sheet is the same type as the type of the first sheet.

When the dimension of a primary transfer roller in the width direction is represented by Wa, the dimension of a counter-sensor member in the width direction is represented by Wb, the dimension of an intermediate transfer belt in the width direction is represented by Wc, and the maximum dimension of a sheet in the width direction is represented by Wd, then the relationship WdWa<WbWc is fulfilled. The transfer position of a test pattern image is a position a predetermined distance away, inward in the width direction, from the edge of the intermediate transfer belt in the width direction. The predetermined distance is twice or more the distance in the width direction from the edge of the intermediate transfer belt in the width direction to the edge of the primary transfer roller in the width direction.

The image forming apparatus includes an image carrier, a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning blade, and a controller. The controller detects printing-coverage rates on a basis of plural areas divided in the longitudinal direction of the image carrier. Upon occurrence of a difference exceeding a specified threshold value among the coverage rates of the plural areas, the controller executes, for a duration of specified aging time, aging process in which the image carrier is driven into rotation in its charged state.

An image forming apparatus includes a photoconductor; a light-emitting element; a deflector to deflect a beam emitted by the light-emitting element to scan the photoconductor with the beam; a photodetector element to detect the beam with multiple sensitivities to determine a write start timing at which the light-emitting element start emitting the beam; and circuitry. The circuitry switches to any one of the multiple sensitivities of the photodetector element; controls the light-emitting element to set a light intensity of the beam; switches the multiple sensitivities according to the light intensity; uses characteristic value information of a relationship between the light intensity and an amount of change in the write start timing to correct a shift in the write start timing; calculates the amount of change while switching to each of the multiple sensitivities; and updates a characteristic value in the characteristic value information based on the amount of change.

An image forming apparatus includes an image forming unit having an image carrier, a charging device, and a development device, so as to perform image formation using toner, an exposure device, an image density sensor, a development voltage power supply, a control unit, and a layer thickness detection mechanism. The control unit can perform calibration, in which density of a reference image formed by the image forming unit is detected by the image density sensor, and the development voltage is adjusted based on a detection result, so as to adjust the density of the toner image. The layer thickness detection mechanism detects thickness of the photosensitive layer. Along with a decrease in the thickness of the photosensitive layer detected by the layer thickness detection mechanism, the control unit stepwisely decreases an upper limit value of the DC voltage from a reference value, when adjusting the development voltage in the calibration.