An image forming apparatus includes an image carrier, an image forming unit, a transfer unit, a detector, a controller, an edge detector, and an abnormality detector. The detector detects developer attached to an image carrying surface at a position between a position where an image is formed and a position where the image is transferred. The controller controls the image forming unit such that a check image including an edge that extends in a direction intersecting the moving direction of the image carrying surface is formed in a region of the image carrying surface that passes through the detection position. The edge detector determines a position of the edge based on a detection status of the developer. The abnormality detector determines whether or not the image former is abnormal based on the position of the edge.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

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.

In an example, a method includes determining an indication of pixel separation for an image region to be printed to a substrate. A power level of a laser light source to address a pixel on a region of a photoconductive surface corresponding to the image region may be adjusted based on the indication of pixel separation to compensate for print spot size variation associated with pixel separation.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

An image forming apparatus includes an image forming unit, a sensor, and a controller. The image forming unit is configured to form a toner image on an image carrier based on image data and transfer the toner image on the image carrier onto a sheet. The sensor is positioned to measure an amount of toner on the image carrier before or after transfer of the toner image onto the sheet. The controller is configured to determine a remaining amount of toner that is discarded or wasted based on the measured amount.

An image forming apparatus includes a brilliant image forming part that forms a brilliant toner image using a brilliant toner, a color image forming part that forms a color toner image using a color toner, and a controller that controls a brilliant deposition amount of the brilliant toner and a color deposition amount of the color toner on a medium, wherein when the brilliant toner image is to be superimposed over the color toner image on the medium, the controller adjusts the brilliant deposition amount for the brilliant toner image in correspondence with a color type and the color deposition amount of the color toner that has been used for the color toner image.

An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit forms a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias, acquires a tilt of a measurement straight line representing a relationship between the change amount of the frequency and a density change amount of the measurement toner image based on the change amount of the frequency and a result of detecting density of the measurement toner image in the density detecting unit, and acquires the charging amount of the toner based on the acquired tilt of the measurement straight line and the reference information in the storage unit.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.