An image forming apparatus includes a first sensor configured to measure a measurement image on a first photoreceptor, a second sensor configured to measure a measurement image on an intermediate transfer member, and a controller. The controller controls the first image forming unit to form first measurement images, wherein the first measurement images are formed along a rotation direction of the first photoreceptor, and controls the first sensor to measure the first measurement images on the first photoreceptor. The controller further controls the first image forming unit and the second image forming unit to form a plurality of measurement images while a rotation speed of the first photoreceptor is being controlled based on a measurement result of the first sensor, wherein the plurality of measurement images is formed along the predetermined direction of the intermediate transfer member.

There is provided image forming apparatus including: photosensitive member; developing roller configured to supply a developer to the photosensitive member; belt to which a developer image is to be transferred from the photosensitive member; sensor; and controller configured to execute a developing bias correcting process for correcting a developing bias to be applied to the developing roller. The developing bias correcting process includes: a setting process for setting testing biases, all of the testing biases being smaller than an old developing bias; a forming process for forming developer images on the belt by using the testing biases set in the setting process; a detecting process for detecting densities of the developer images formed in the forming process by the sensor; and a calculating process for calculating the developing bias based on the densities of the developer images detected in the detecting process.

Provided is an operation method of an image forming apparatus, the operation method including according to a color registration pattern that is a standard for determining an overlapping degree of respective color images of a plurality of colors to form a color image, transferring respective developers with the plurality of colors onto an intermediate transfer body; obtaining patch data of patches of the plurality of colors transferred according to the color registration pattern onto the intermediate transfer body. The patch data is compared with reference patch data corresponding to the color registration pattern, and based on a result of the comparing, noise data corresponding to noise is detected from the patch data. Standard patch data is obtained by removing the noise data from the patch data, and performing color registration based on the standard patch data.

An image forming apparatus includes a processor. The processor is configured to emit a laser beam reflected by a polygon mirror, the polygon mirror rotated by a polygon motor, form an image based on a latent image carried on a photoconductor by the laser beam, store an execution frequency of an image quality self-check of the image formed and a rotation duration of the polygon motor during a standby operation period of image formation, accept a change in the execution frequency, change the rotation duration based on the change in the execution frequency, execute the image quality self-check based on the execution frequency, and continuously rotate the polygon motor during the standby operation period based on the rotation duration stored.

An image forming apparatus that has an image bearing member to be removably mounted to the image forming apparatus includes an intermediate transfer member, a toner detection unit, an exposure device, a forming unit, and a judgment unit. The judgment unit judges a mounting state of the image bearing member based on whether the toner detection unit detects a toner image transferred on a surface of the intermediate transfer member. When the image bearing member is mounted, first and second patterns of toner images are formed apart by a predetermined interval in a rotation direction of the intermediate transfer member. Where the toner detection unit detects the first and second patterns of toner images, the judgment unit judges that the image bearing member is mounted. Where one of the first and second patterns is not detected, the judgment unit judges that the image bearing member is not mounted.

A detection unit executes correction control of an image formation condition on a basis of a detection result of reflected light when infrared light is radiated to a test patch, which is transferred from a photosensitive drum to an intermediate transfer belt, and the intermediate transfer belt, wherein the intermediate transfer belt has a base layer which is thickest among a plurality of layers forming the intermediate transfer belt in a thickness direction of the intermediate transfer belt and to which an ion conductive agent is added, and an inner surface layer which has a light transmittance lower than that of the base layer.

An image forming apparatus includes a transfer belt, a forming unit, a detection unit, a correction unit, a drive system, a determination unit, and a notification unit. The forming unit forms an image-misregistration detection pattern of a plurality of colors on the belt. The correction unit corrects an image misregistration of an image of each color based on a detection result of the pattern. The determination unit detects a difference amount between a pattern interval of the pattern on the belt and a pattern interval serving as a reference value for each color and determines that an abnormality has occurred in a driving state of the drive system, in response to the difference amount equal to or greater than a threshold value. The notification unit notifies occurrence of the misregistration when the determination unit determines that the driving state is abnormal, based on the difference amount of any one color.

In one example in accordance with the present disclosure, a print device is described. The print device includes multiple consumable components. Each consumable component includes a portion of a hardware-based identifier. At least one sensor of the print device reads multiple portions of the hardware-based identifier. A controller of the print device combines the multiple portions of the hardware-based identifier and verifies the hardware-based identifier to determine an authenticity of the multiple consumable components.

In an image forming apparatus, a calibration controller controls an exposure device to form a toner patch image for calibration in a non-printable area outside a printable area in a main scanning direction, and executes at least one of density adjustment and gradation adjustment based on a density measurement value of the toner patch image. A toner refresh controller controls the exposure device to form a toner band for toner refresh in accordance with a coverage rate. Further, when the length of the toner band to be formed in the non-printable area exceeds a predetermined threshold value, the toner refresh controller forms at least a part of the toner band to be formed in the non-printable area in parallel with a subsequent page image.

An image forming apparatus includes a developing roller, a photoconductor drum, a density detector, a current detector, and a controller. The developing roller carries a toner. The photoconductor drum carries a toner patch. The density detector detects toner density of the toner patch. The current detector detects developing current flowing to the toner patch. The controller calculates an inclination of an approximate straight line approximating a relation between the toner density and the developing current. The developing roller develops three or more toner patches, different in toner density and different in developing current from one another, on the photoconductor drum. The controller calculates the inclination, using different mathematical expressions depending on whether three toner patches or four toner patches are provided.