An image forming apparatus includes an intermediate transfer body, a plurality of image formation units arranged in a direction along which the intermediate transfer body moves. The plurality of image formation units includes a first image formation unit and at least one second image formation unit disposed downstream of the first image formation unit.

An image forming apparatus includes a developer information acquisition unit. The developer information acquisition unit performs a developer deterioration information acquisition operation. In the developer deterioration information acquisition operation, the developer information acquisition unit acquires a tilt of a measurement straight line representing the relationship between the change amount of the frequency in a first measurement toner image forming operation and the density change amount of the measurement toner image based on the change amount of the frequency in the first measurement toner image forming operation and a result of detecting density of the measurement toner image in a density detecting unit, and acquires a toner charging amount based on the acquired tilt of the measurement straight line and the reference information in the storage unit so as to acquire information relating to deterioration of developer based on the acquired toner charging amount.

An image forming apparatus includes an image bearer, a driver, an image forming device, a sensor, and circuitry. The driver drives and rotates the image bearer. The image forming device forms a toner image on the image bearer driven and rotated by the driver. The sensor emits light to the image bearer and receives reflected light. The circuitry controls the driver and the image forming device to form a first toner image with a first color and a second toner image with a second color different from the first color. The circuitry controls the sensor to detect specularly reflected light and diffusely reflected light from the first toner image and the second toner image. The circuitry calculates an amount of misalignment of the first toner image and the second toner image based on a value of the specularly reflected light and a value of the diffusely reflected light.

In the first charge amount acquisition operation, based on density of a plurality of toner images for measurement or based on a direct component of a developing current at the time of forming the plurality of toner images in addition to the density of the plurality of toner images for measurement, the charge amount acquisition section acquires a first toner charge amount that is a charge amount of toner included in the toner image for measurement. In the second charge amount acquisition operation, based on the toner density detected at the time of image formation and a relationship between the first toner charge amount and the toner density detected in the first charge amount acquisition operation, the charge amount acquisition section acquires a second toner charge amount that is a charge amount of the toner in the development device.

An image forming apparatus includes: a plurality of image forming parts each of which transfers a toner image to the transfer medium, the plurality of image forming parts being arranged from an upstream side to a downstream side along a moving direction of the transfer medium; a density detector that detects a density of the toner image; and a hardware processor that performs image stabilization control in which a plurality of patch images is formed while levels of parameters of image formation are changed for each of the image forming parts and the parameters are corrected based on respective densities of the patch images detected by the density detector.

An image forming apparatus controls a first image forming unit and a second image forming unit to form a plurality of pattern images. The plurality of pattern images includes a first pattern image formed by the first image forming unit, a second pattern image formed by the second image forming unit, a plurality of third pattern images that are formed by the first image forming unit and have different tones from one another, and a plurality of fourth pattern images that are formed by the second image forming unit and have different tones from one another. The image forming apparatus obtains data that has been output from a sensor and is related to the plurality of pattern images, and generates the conversion condition based on the data.

An image forming apparatus includes a latent image bearer, a charger, an exposure device, a developing device, a toner adhesion amount detector, and control circuitry. The control circuitry controls the charger, the exposure device, and the developing device to form the detection toner pattern shorter than a circumferential length of the latent image bearer in a circumferential direction of the latent image bearer at an area of the latent image bearer including at least a part of an opposite portion of the latent image bearer opposite the charger when the latent image bearer stops rotation, controls the toner adhesion amount detector to detect the toner adhesion amount of the detection toner pattern, and executes a refreshing operation to recover the surface of the image bearer from a deteriorated state due to a discharge product based on a result of the detection toner pattern detected by the toner adhesion amount detector.

A detecting apparatus includes: a light emitting element which emits light toward a detection material; a light receiving element which receives reflected light from the detection material; and an apparatus main body having an opening/closing member which opens and closes an opening through which light emitted from the light emitting element and reflected light from the detection material pass through, the apparatus main body being capable of moving between a first position where the apparatus main body comes into contact with the detection material and a second position where the apparatus main body separates from the detection material, and the opening/closing member being configured to open when the apparatus main body moves to the first position and to close when the apparatus main body moves to the second position.

An image forming apparatus includes an image bearing member; an image transfer device for transferring a toner image from aid image bearing member to a sheet; an application device for applying a transfer voltage to the image transfer device; and a controller for controlling an output mode operation for outputting a predetermined chart in which test halftone toner images transferred with different transfer voltages are formed to adjust the transfer voltage. When outputting a maximum size of the chart, the controller forms the test toner images in a region within 50 mm from an edge in a width direction perpendicular to a feeding direction of the sheet.

An image forming apparatus includes an image former that forms and fixes an image of the adjustment chart on the sheet, an image reader that reads the adjustment chart formed on the sheet, a front and back adjuster that performs the front and back adjustment on a basis of the adjustment chart that is formed and fixed by the image former and read by the image reader, an image coverage rate calculator that calculates in advance an image coverage rate of the sheet included in one job to be executed by the image former, and a chart coverage rate determiner that determines a coverage rate of the adjustment chart to be formed on a front side of the sheet on a basis of the image coverage rate calculated by the image coverage rate calculator.