A differential correction data generating unit measures two density characteristics at a reference linear velocity and another linear velocity from scanned images of two test charts printed at the reference linear velocity and the another linear velocity, and generates differential correction data as a difference between correction amounts for the measured two density characteristics. A correction amount adjusting unit measures a density characteristic at the reference linear velocity from an adjustment toner pattern formed on an intermediate transfer member, and thereby adjusts a correction amount for the density characteristic at the reference linear velocity. A density characteristic of a printing image is corrected, (a) for the reference linear velocity, on the basis of the correction amount at the reference linear velocity, and (b) for the another linear velocity, on the basis of the correction amount at the reference linear velocity and the differential correction data.

In an image forming apparatus, a storage portion stores a target adhesion amount of toner to adhere to an image bearing member at each of gradation levels as a target gradation level and a setting value of a control parameter used for control on the image forming portion at the target gradation level. A first control processor makes an adhesion amount sensor measure an actual adhesion amount corresponding to the setting value and thereafter compares a resultant measured value and the target adhesion amount and corrects the setting value if needed in association with at least one of the target gradation levels as a subject. A second control processor makes the image forming portion output a calibration image used for correcting the target adhesion amount using a period when the first control processor performs processing if there arises a need to correct the target adhesion amount associated with the subject.

An image defect predictive diagnostic apparatus includes an acquisition unit and a notification unit. The acquisition unit acquires first characteristic values and second characteristic values from an image forming apparatus that forms an image by using an electrophotographic process. The first characteristic values include at least one of (i) toner concentrations and (ii) developing potentials. The first characteristic values have an influence on developability. The second characteristic values are different from the first characteristic values. The notification unit predicts occurrence of a dot image which has no relationship with the image by using the first characteristic values and the second characteristic values which are acquired by the acquisition unit, and that makes notification.

An image forming apparatus includes an image forming unit configured to form an image on a sheet based on image forming condition, a reader configured to convey the sheet and read a test image on the sheet while the sheet is conveyed, and a controller configured to control the image forming unit to form the image and the test image on a same sheet, control the reader to read the test image on the same sheet, and generate the image forming condition for adjusting a density of an image to be formed by the image forming unit, based on a reading result of the test image by the reader.

According to an embodiment, an image forming apparatus includes an image forming device, a scanning device, and a controller. The image forming device forms a first test image and forms a second test image. The scanning device scans the first test image with a first amount of emitted light corresponding to a first input value and scans the second test image with a second amount of emitted light corresponding to a second input value. The controller selectively executes any one of a first correction process, a second correction process, or a third correction process on the basis of an event change.

A toner concentration sensing apparatus includes a first acquisition processing portion, a second acquisition processing portion, and a third acquisition processing portion. The first acquisition processing portion acquires a first sensing value corresponding to light reflected by a first region of an image-carrying member where a toner image is not formed. The second acquisition processing portion acquires a second sensing value corresponding to light reflected by a second region of the image-carrying member where a toner image has been formed. The third acquisition processing portion acquires a component ratio of a component in the second sensing value, that corresponds to light reflected by toner adhered onto a surface of the image-carrying member, using a specific calculation formula determined based on a first relational expression based on the first sensing value and a second relational expression not based on the first sensing value, and the second sensing value.

An image forming apparatus includes a first image forming unit configured to form a first image in a chromatic color, a second image forming unit configured to form a second image in black, an intermediate transfer member, a sensor, a first adjustment unit configured to adjust the image forming position for the black based on an adjustment value, a second adjustment unit configured to adjust image forming position based on an adjustment condition, and a generation unit configured to generate the adjustment condition. The generation unit generates a first adjustment condition based on a user instruction relating to a first test image having chromatic color on a sheet input from the input unit. The generation unit generates a second adjustment condition based on the reading result of the second test image having black on a sheet from a reading device.

Provided is an image forming apparatus having high usability and securing both image quality and productivity. The image forming apparatus changes a rotational speed of a secondary transfer member depending on a basis weight of a sheet. The image forming apparatus performs digital sub-scanning scaling of correcting image data and polygon sub-scanning scaling of controlling a scanning speed during image formation so as to cancel out image deformation caused by change in rotational speed of the secondary transfer member. When giving priority to image quality, the image forming apparatus performs processing of the digital sub-scanning scaling and the polygon sub-scanning scaling, and when giving priority to productivity, the image forming apparatus performs only processing of digital sub-scanning scaling.

An image forming apparatus includes a toner image forming unit, a transfer member, and a driving source. An execution unit corrects image misalignment on the basis of a detection result of a test one image when no toner image exists in a transfer portion. An input unit associates first and second containers of recording material with either first and second groups regarding characteristics of the recording material. A setting is possible in which, if the recording material stored in the container associated with the first and second groups is used for the image formation, the driving source is driven at first and second speeds. Whether to conduct the correction before the current image formation is determined depending on the group associated with the container in which the recording material on which the previous image formation is conducted is stored.

An image forming apparatus including: a toner image forming unit forming a toner image on an intermediate transfer member; a transfer member transferring the toner image on the intermediate transfer member to a recording material in a transfer portion; a driving source applying driving force to the transfer member independently of an intermediate transfer member driving source; an execution unit correcting image misalignment on the basis of a detection result of a test toner image on the intermediate transfer member when no toner image exists in the transfer portion; a container storing the recording material; and an input unit associating the container with a group related to basic weight and surface properties of the recording material. The apparatus includes a driving unit driving the driving source at a speed corresponding to the group if the recording material stored in the container associated with the group is used for image formation.