An exposure device irradiates a photoconductor with light on the basis of an exposure signal and thereby forms an electrostatic latent image. A toner amount calculating unit (a) determines a distribution pattern of the electrostatic latent image on the basis of the exposure signal, (b) determines an electric field variation level of a target pixel, (c) determines an electric field intensity of the target pixel on the basis of a value of the target pixel in the distribution pattern and the electric field variation level, and (d) determines a toner consumption amount corresponding to the electric field intensity. Further, using spatial filters independently of each other in a primary scanning direction and in a secondary scanning direction, the toner amount calculating unit determines the electric field variation level on the basis of (a) the distribution pattern or (b) the exposure signal.

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.

An image forming apparatus includes first to third adjustment processing portions. The first adjustment processing portion adjusts an emission light amount of a light-emitting portion of a first sensor based on an electric signal output from a light-receiving portion of the first sensor and corresponding to regular reflection light reflected by a non-toner-adhering surface of an image-carrying member. The second adjustment processing portion adjusts an operation condition of an image forming portion based on a toner concentration of a first toner image in a specific color, that has a concentration smaller than a predetermined saturation concentration. The third adjustment processing portion adjusts an emission light amount of a light-emitting portion of a second sensor based on an electric signal output from a light-receiving portion of the second sensor and corresponding to diffuse reflection light reflected by a second toner image in the specific color, that has a predetermined reference concentration.

An image forming apparatus includes an image forming unit includes a photosensitive member; a charging unit configured to uniformly charge the photosensitive member; an exposure unit configured to form an electrostatic latent image on the photosensitive member by scanning the charged photosensitive member with laser light; and a developing device configured to develop the electrostatic latent image to form an image on the photosensitive member, a reading unit configured to read a test image, which is formed by the image forming unit, for detecting image density of the image, and a controller configured to: control the image forming unit to form the test image; detect periodic fluctuation of the image density based on a detection result of the test image which is acquired by controlling the reading unit to read the test image; and correct an image forming condition to suppress the detected fluctuation.

An image forming apparatus includes an image forming device to form an image on an image bearer based on a prescribed image-forming condition, and circuitry to change the prescribed image-forming condition and correct image-density unevenness in an image-width direction orthogonal to an image conveyance direction of the image bearer. In the image forming apparatus, the circuitry calculates a corrective value of the prescribed image-forming condition for each one of positions in the image-width direction, based on unevenness-in-density corrective values for the multiple positions in the image-width direction and relational values indicating a relation between the multiple unevenness-in-density corrective values and the corrective value of the prescribed image-forming condition, and the circuitry corrects the image-density unevenness in the image-width direction based on the corrective value of the prescribed image-forming condition. In the image forming apparatus, the multiple relational values correspond to portions in the image-width direction.

According to one embodiment, an image forming apparatus includes an image forming unit to form an image on a sheet and a sensor with a light emitting part having a light emission intensity that changes according to an input voltage level and a light receiving part that outputs an output value that changes according to the amount of incident light. The sensor is configured to detect a toner density of the image formed by the image forming unit. A power supply unit is provided to supply power to the light emitting part and change the input voltage level of the power supplied to light emitting part in a predetermined sequence until an end condition is satisfied during an inspection operation. A controller is configured to make an abnormality determination based on a state of the sensor when the end condition is satisfied during the inspection operation.

According to one embodiment, an image forming apparatus includes an image forming unit to form an image on a sheet and a sensor with a light emitting part having a light emission intensity that changes according to an input voltage level and a light receiving part that outputs an output value that changes according to the amount of incident light. The sensor is configured to detect a toner density of the image formed by the image forming unit. A power supply unit is provided to supply power to the light emitting part and change the input voltage level of the power supplied to light emitting part in a predetermined sequence until an end condition is satisfied during an inspection operation. A controller is configured to make an abnormality determination based on a state of the sensor when the end condition is satisfied during the inspection operation.

In the image forming method, a halftone image is generated by performing halftone processing for an input image, a scanned image of a printed material on which on which the halftone image is printed is obtained, and a failure component of an image forming apparatus is identified based on a difference between the scanned image and the input image. In the generation, the halftone image is generated by representing a dot pattern of a halftone portion in a case where the input image is a test image for the failure diagnosis by a dot pattern whose frequency is relatively higher than that of a dot pattern that is applied to the halftone portion in a case where the input image is an image other than the test image.

An image forming apparatus includes a plural image forming units each having a plural image forming sections, and an intermediate transfer body on which toner images formed by the plural image forming sections are primarily transferred, a plural secondary transfer units that are provided corresponding to the plural image forming units, and secondarily transfer the toner images of the intermediate transfer body to a recording medium, and a processor, in which each image forming unit has the image forming section of the same color, and the processor is configured to: in response to an instruction to output a color chart of the same color, execute a mode in which the color chart of the toner image having a density of intermediate gradation, formed by the image forming section of the same color for each image forming unit, is secondarily transferred to the recording medium and output.

An image-forming apparatus includes a generating unit that generates correction data for correcting an unevenness in light amount of an exposure head using a read image of a correction chart, and a correction unit that corrects image data for image formation based on the correction data. The exposure head includes light-emitting chips each of which includes light-emitting elements. The correction chart includes a plurality of regions arranged in a direction, a first reference mark located on one side of the regions, and a second reference mark located on the other side of the regions. The generating unit determines partial regions respectively formed by the light-emitting chips within the regions based on positions of the first and second reference marks in the read image of the correction chart, and generate the correction data based on a result of measurement on the partial regions.