An image forming apparatus includes an image forming section, an optical scanning device, an image density sensor, and a control unit. The optical scanning device scans the surface of the image carrying member with light emitted from light sources to form an electrostatic latent image. The control unit can perform light amount calibration to adjust the exposure amount of the light scanning device based on the density of a reference image detected by the image density sensor. The reference image used for light amount calibration has a dot pattern in which as many individual dots as there are light sources are arrayed at regular intervals in the main scanning direction. The dot pattern is formed repeatedly in the main and sub scanning directions. The dots forming the dot pattern are arranged at different positions in the sub scanning direction to be displaced in units of pixels from each other.

A control portion can perform printing operation and to determine a transfer voltage for performing it, transfer voltage setting operation. When performing adjusting operation, the control portion estimates the amount of static charge of toner in a development device to determine the transfer voltage based on the estimated amount of static charge of the toner and the resistance value of a transferring member previously stored in a memory.

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.

An image forming device includes a controller, an image former that causes a color material to adhere to a sheet for each of multiple pixels arranged in a first direction, and a sheet feeder that feeds the sheet in a second direction. The controller determines whether a first color material used for a first pixel out of the multiple pixels is identical to a second color material used for a second pixel adjacent to the first pixel on a training end side in the second direction with respect to the first pixel, and executes a correction process of correcting a density of the first color material when it is determined that the first color material is identical to the second color material, the density of the first color material is lower than a first density, and a density of the second color material is equal to or higher than a second density that is equal to or higher than the first density.

An image forming system generates second image data representing a result of a reading unit reading an image on a sheet, corrects the second image data using correction data, the correction data being data obtained on the basis of image data obtained by the reading unit reading a predetermined image formed on the sheet by an image forming unit and image data corresponding to the predetermined image, and inspects, on the basis of the corrected second image data and a first image data, an image formed on the sheet on the basis of the first image data.

An image forming apparatus includes plural development devices that accommodate different types of developers from each other, a first replenishment unit that replenishes a developer to at least one development device of the plural development devices in a case where a density of the developer in the at least one development device is a predetermined value, a second replenishment unit that replenishes the developer to a remaining development device of the plural development devices in a case where a density of the developer in the remaining development device is a predetermined value, and a control unit that controls the first replenishment unit to be activated at a same timing as an activation timing of the second replenishment unit.

An image formation apparatus may include: a first image formation unit including a storage part and configured to form a glitter developer image; and a controller. The controller may be configured to control the first image formation unit, (i) upon forming a glitter image on a medium based on predetermined print data when a remaining amount of a glitter developer in the storage part is a first remaining amount, to form the glitter developer image with a ratio of the glitter image per unit area being a first area ratio, and (ii) upon forming the glitter image on the medium based on the predetermined print data when the remaining amount is a second remaining amount less than the first remaining amount, to form the glitter developer image with the ratio of the glitter image per unit area being a second area ratio greater than the first area ratio.

An image forming apparatus includes a rotatable image bearing member, an image forming portion, a transfer portion, a cleaning blade, and a controller configured to carry out control so as to execute a predetermined cleaning operation At least in a predetermined range of a leading end portion of the predetermined toner image with respect to a first direction which is a surface movement direction of the image bearing member, when the predetermined toner image is viewed per unit area of 1 mm in each of the first direction and a second direction perpendicular to the first direction, the predetermined toner image includes a plurality of print portions extending along a predetermined direction and formed at different positions with respect to the second direction, and the predetermined direction forms an angle of 30 or less between itself and the first direction.

An image forming apparatus includes an image former, a detector, and circuitry. The image former forms a toner pattern with a first line screen; and forms a toner image based on image data, with a second line screen. The detector detects density unevenness of the toner pattern, formed by the image former, in a main scanning direction. The circuitry is configured to calculate a first correction amount from the density unevenness detected by the detector; create a gradation correction table that reduces the density unevenness based on the first correction amount; and correct the first correction amount by a second correction amount corresponding to the second line screen, in a case where the first line screen is different from the second line screen.

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.