In a case where image correction is performed to deal with a registration shift and a color shift in an electrophotographic image forming apparatus, it is made possible to obtain a sufficient correction effect even in a high-quality mode. The image forming apparatus having a first printing mode and a second printing mode includes: at least one controller, having at least one processor which executes instructions stored in at least one memory, at least one circuitry or a combination of the at least one processor and the at least one circuitries, being configured to: perform scan line changing processing to shift an image in units of pixels in a sub scanning direction at a predetermined scan line changing point in a main scanning direction in accordance with characteristics of a laser scan line; and correct a tone level value of a pixel of interest in an image after the scan line changing processing by referring to a tone level value of a pixel adjacent to the pixel of interest in a sub scanning direction.

The present invention performs inplane uneven density correction that suppresses a number of tone correction properties and has few correction residuals. Accordingly, a holding unit of an apparatus of the present invention holds a plurality of tone correction properties respectively corresponding to a plurality of spot diameters that divide a range of a spot diameter of a light exposed on a surface of a photoreceptor by a predetermined interval. In addition a setting unit sets a tone correction property selected from the plurality of tone correction properties based on a spot diameter on the photoreceptor for a pixel corresponding to pixel data C. A correction unit corrects the pixel data C based on the set tone correction property, to generate tone correction data Cc.

Provided is an image forming apparatus configured to form an image on a sheet. The image forming apparatus includes an image bearing member configured to rotate in a predetermined direction, and an image forming unit configured to form an image on the image bearing member based image data converted based on a conversion condition. A controller of the image forming apparatus controls the image forming unit to form a plurality of measurement images different in density along the predetermined direction of the image bearing member, detects those plurality of measurement images, and generates the conversion condition based on detection results of the plurality of measurement images. The controller controls the image forming unit to form the plurality of measurement images in a dispersed manner in terms of positions of the plurality of measurement images on the image bearing member in accordance with periodic unevenness that occurs in the measurement images.

The circuit substrate includes at least two lands formed on a substrate, wherein one electrode is to be mounted on the at least two lands, an electronic part having electrodes, one of the electrodes is soldered on the at least two lands with solders whose amounts are adjusted by a metal mask having at least two opening parts, positions of the at least two opening parts corresponding to the at least two lands when the solders are applied and melted, areas of the at least two opening parts being different with each other, wherein a height of one of the solders is different from a height of the other of the solders according to the difference of the areas of the at least two opening parts of the metal mask, whereby the electronic part is mounted on the circuit substrate in an inclined state.

In a case where image correction is performed to deal with a registration shift and a color shift in an electrophotographic image forming apparatus, it is made possible to obtain a sufficient correction effect even in a high-quality mode. The image forming apparatus having a first printing mode and a second printing mode includes: at least one controller, having at least one processor which executes instructions stored in at least one memory, at least one circuitry or a combination of the at least one processor and the at least one circuitries, being configured to: perform scan line changing processing to shift an image in units of pixels in a sub scanning direction at a predetermined scan line changing point in a main scanning direction in accordance with characteristics of a laser scan line; and correct a tone level value of a pixel of interest in an image after the scan line changing processing by referring to a tone level value of a pixel adjacent to the pixel of interest in a sub scanning direction.

An image forming apparatus controls a generation circuit to modulate a DC component of a developing voltage based on a first correction component such that a density unevenness is reduced. The image forming apparatus further restricts the first correction component for modulating the DC component of the developing voltage such that fogging of toner that may occur on a non-exposure region which is not exposed by an exposure unit and adhesion to a photosensitive member of carrier included in a developer are reduced.

Provided is an image formation device including a photoreceptor configured to carry a toner image and a developer configured to form the toner image on a surface of the photoreceptor and configured such that the developer is a replaceable development unit, the image formation device including: a development bias application section configured to apply a development bias to between the photoreceptor and the developer; a stabilization control section configured to perform image stabilization control of determining a development bias value to be used in future by changing the development bias while measuring a density of the toner image formed by the developer, thereby obtaining the toner image with a target density; and a life determination section configured to determine expiration of use of the development unit when the development bias value determined by the stabilization control falls outside a preset acceptable range.

An image forming apparatus forms a first image by adjusting a photosensitive member potential to a first charging potential and adjusting a developing potential to a first developing potential, and forms a second image by adjusting the member potential to a second charging potential and adjusting the developing potential to a second developing potential, but not causing an exposure unit to expose a photosensitive member, and forms a third image by adjusting the developing potential to a third developing potential, but not causing a charging unit to charge the member and not causing the exposure unit to expose the member. The apparatus detects a streak image based on read data of the first, second and third images, and read data corresponding to a non-image region of the test sheet.

An image forming apparatus includes an image forming device, an image density detector, and a processor. The processor controls the image forming device to form a first test toner image, and controls the image density detector to detect an image density at the plurality of positions of the first test toner image. The processor adjusts an image forming condition so that the image density detected at each of the plurality of positions becomes a target image density, controls the image forming device to form a second test toner image based on the adjusted image forming condition, controls the image density detector to detect an image density at the plurality of positions of the second test toner image, determines whether a streak exists in the second test toner image based on the detected image densities, and executes a countermeasure to prevent an occurrence of the streak.

According to one embodiment, an image processing device capable of removing a horizontal streak that may show when a document is scanned and made into a file is provided. An image processing device according to one embodiment includes: an image processing unit configured to generate smoothing image data obtained by applying smoothing to image data, and save, as an image file, non-smoothing image data in which smoothing is not applied to the image data when a difference between the non-smoothing image data and the smoothing image data is equal to or greater than a threshold value, and the smoothing image data when the difference is smaller than the threshold value; and a storage unit configured to save the image file.