An image forming apparatus according to an embodiment includes an image forming unit, and a processor. The image forming unit forms an image on a printing medium. The processor performs user authentication and, upon performing the user authentication, determines whether or not an image stabilization process should be performed in the image forming unit. The processor then instructs the image forming unit to perform the image stabilization process according to a result of the user authentication.

An image forming apparatus includes a control unit configured to be able to perform density adjustment control of forming a reference toner image for image density control on an image bearing member and changing a target value of a toner density based on an image density of the reference toner image detected by an image density detection unit. The control unit limits the target value of the toner density within a predetermined range, and changes frequency of execution of the density adjustment control based on the fact that the target value of the toner density is placed at a boundary value.

An image forming apparatus includes an image forming portion, an exposure device, an image density sensor, and a control portion. The control portion can, by adjusting the development voltage based on the image density of a reference image and the amount of exposure from the exposure device, perform image density correction to adjust the image density. The control portion predicts the toner charge amount based on a formation condition of the reference image and the image density of the reference image and determines the timing of performing the image density correction next time based on the rate of change of the toner charge amount calculated using a first toner charge amount predicted when the image density correction was performed last time, a second toner charge amount predicted when the image density correction is performed this time, and the interval between the image density correction performed last time and this time.

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 apparatus includes: an image forming unit configured to form an image pattern on a medium, a predetermined image repeatedly appearing in a first cycle in a sub scanning direction in the image pattern; a density detector configured to optically detect a density of the image pattern in the sub scanning direction; a cyclic image detector configured to detect a feature image having a second cycle corresponding to the first cycle in accordance with a result of the detection; and a state determining unit configured to determine whether a cycle depending on an outer circumference of a rotary member included in the image forming apparatus corresponds to the second cycle when the feature image is detected by the cyclic image detector, and determine that a state of the rotary member has deteriorated when the cycle depending on the outer circumference is determined to correspond to the second cycle.

Changing of a peripheral speed ratio, resulting in change of the developer amount per unit area, enables the detection unit to detect the developer amount with sufficient accuracy.

An image forming apparatus is provided. The image forming apparatus includes a sensor configured to sense a toner concentration, a processor configured to determine at least one of a coring level and a total area coverage (TAC) level according to the detected toner concentration, and an image former configured to print the rendered print data.

An image forming apparatus includes an image forming unit configured to form an image, a reference member, a sensor including a substrate, a light-emitting element provided on the substrate, a light-receiving element provided on the substrate, and a blocking member provided between the light-emitting element and the light-receiving element on the substrate, the sensor configured to output an output value based on a light reception result of the light-receiving element, a memory storing data related to a relationship between a measurement condition and an offset value, and a controller configured to control the sensor based on a plurality of measurement conditions to acquire an output value corresponding to a measurement result of reflected light from the reference member, and determine a measurement condition for measuring the image based on the acquired output value and the data stored in the memory.

An image forming apparatus includes: an image carrier; a developing unit which supplies a toner contained in a developer to the image carrier; a lubricant supply unit which supplies a lubricant to the image carrier; a lubricant amount detection unit which detects an amount of the lubricant which is supplied to the image carrier from the lubricant supply unit and is thereafter incorporated into the developing unit from the image carrier; and a control unit which controls the developing unit to discharge the lubricant from the developing unit according to the amount of the lubricant detected by the lubricant amount detection unit.

An image forming apparatus includes an image forming unit, an acquisition unit, a fixing unit including a heating member and a pressure member forming a nip, a temperature detecting unit, and a control unit. In a case where a toner density of a toner image on a k-th recording material of a plurality of recording materials is less than the toner density of the toner image on a (k-1)-th recording material of the plurality of recording materials, k being an integer greater than or equal to two, the control unit sets a fixing temperature of the k-th recording material to a temperature which is greater than a predetermined temperature predetermined based on image information of the toner image to be formed on the k-th recording material.