An image forming apparatus includes a detecting unit configured to detect a test image formed on an image carrier; and an obtaining unit configured to obtain a color misregistration amount using a detection result of the test image by the detecting unit. The test image includes one or more basic patterns; each one of the one or more basic patterns includes a first pattern group and a second pattern group disposed at different positions with respect to a conveyance direction of the image carrier; the first pattern group and the second pattern group each include a plurality of V-shaped patterns; and the V-shaped patterns of the first pattern group and the second pattern group have an axisymmetrical shape about an axis corresponding to a width direction orthogonal to the conveyance direction.

An image forming apparatus includes a developing roller configured to develop an electrostatic latent image on a photosensitive drum to form a toner image; a belt onto which the toner image is transferred; a detection unit configured to detect a density of an image for detection formed on the belt; and a controller configured to perform hue adjustment based on a detection result of the detection unit. The image forming apparatus performs image formation in a second mode using a color gamut different from a color gamut in a first mode, and the controller obtains a lookup table, which indicates a correlation between image data to be used and input image data in the second mode, based on the detection result in the first mode and a correlation of density between the first mode and the second mode.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

An image forming apparatus includes: a transporter; an image former; a reflective optical sensor; an image density adjuster; and a controller. The image former includes: a photoreceptor; a charger; an exposer; a developer; a transferor; and a fuser. The reflective optical sensor is provided opposite to the photoreceptor across a conveyance path. During image density adjustment, the controller forms a predetermined patch toner image on the photoreceptor, irradiates the patch toner image with light, and control the image density adjuster to adjust image density based on reflected light from the patch toner image. During image forming, the controller causes the reflective optical sensor to emit light on timing that a predetermined leading edge area of the recording area passes, and decides based on reflected light therefrom whether a width in the main scanning direction of a recording medium is longer than a predetermined reference length.

An image forming apparatus includes an image bearing member, an exposure unit, a developing member, and a control unit. The exposure unit exposes a surface of the image bearing member to light to form an electrostatic latent image. The developing member develops the electrostatic latent image by using toner to form a toner image. In image formation based on input image data, the control unit uses the exposure unit to control a maximum gradation value of the toner image to be formed on the image bearing member surface, based on a repetition length of a dither pattern. The control unit performs control so that the maximum gradation value is larger in a case where a first dither pattern having a first length as the repetition length is used than where a second dither pattern having a second length longer than the first length as the repetition length is used.

An image forming apparatus, configured to operate in first and second modes of which color gamut is different from each other, includes an exposure unit configured to expose a photosensitive drum; a developing roller configured to form a toner image; a detection unit configured to detect density of the toner image transferred to an intermediate transfer member; and a controller configured to adjust the density based on a value of input image data. A dithering process for the controller's controlling of the exposure unit is different depending on whether the operation is in the first mode or the second mode, and in at least a part of the input image data, the density of the toner image formed by the dithering process in the first mode is higher than the density of the toner image formed by the dithering process in the second mode.

It is an object of the present invention to diagnose image quality of a print image without using an open communication network and output the print image, a diagnosis result of image quality, and information of the print parameters while avoiding disclosure of confidential information to users. A test print control portion causes a print device to execute a test print process to form a test image on a sheet. An image quality diagnosis portion diagnoses image quality of the test image included in the image read by an image reading device. A code image generating portion generates a code image that represents information of print parameters adopted in the test print process. An output control portion causes an output device to output a diagnosis image that includes an image representing a diagnosis result of image quality of the test image, and the code image.

An image forming apparatus includes: an image. forming unit configured to form an image on an image bearing member based on an image forming condition, an optical sensor including: a light emitter configured to irradiate the image bearing member with light based on a supplied current; and a light receiver configured to receive reflected light of the light emitted from the light emitter; a temperature detector configured to detect a temperature of the optical sensor; and a controller configured to: control the image forming unit to form a detection image on the image bearing member; control the optical sensor to detect reflected light from the detection image; and adjust the image forming condition based on a result of detecting the detection image by the optical sensor. The controller is configured to control the light emitter to emit light; and generate a correction condition.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

An image forming apparatus includes a detection unit that optically detects a density of a reference toner image for density measurement formed on an image carrier. Either a first detection method for detecting the density of the reference toner image by receiving specularly reflected light reflected by the image carrier and the reference toner image for density measurement formed on the image carrier or a second detection method for detecting the density of the reference toner image by receiving diffusely reflected light from the image carrier and the reference toner image, is selected in accordance with color information of a toner, the color information being stored beforehand in a storage unit, and the density of the reference toner image is optically detected.