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 includes a photoreceptor, an exposure unit, a developing unit, and a control unit. The control unit sets the toner-layer-forming electric potential difference lower than an electric potential when forming the image on the print medium, forms a combined patch for calibration by the set toner-layer-forming electric potential difference for calibration, so as to adjust the developing-bias potential by measuring a print density of the formed combined patch. The combined patch includes a first patch and a plurality of second patches. The plurality of second patches have a width within a range of 0.2 mm to the predetermined value in the peripheral-velocity direction of the photoreceptor, extend with a length equal to or more than the predetermined value in the rotation-shaft direction of the photoreceptor, and are arranged at a predetermined interval in the peripheral-velocity direction of the photoreceptor.

An image forming apparatus comprising: an image forming unit configured to convey a recording medium, and form an image on the recording medium based on an image forming condition; and a controller configured to control the image forming unit to form a test image and a scale image extending a conveyance direction in which the recording medium is conveyed, obtain user instruction information related to a density fluctuation of the test image in the conveyance direction, and to generate the image forming condition to suppresses image density unevenness in the conveyance direction to an image to be formed by the image forming unit based on the user instruction information.

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.

An image forming apparatus is configured to control 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 is further configured to restrict 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.

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, 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, and 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.

A sensor includes a light emitter and a photodetector. The light emitter outputs light with which a toner pattern or a surface material of an image carrier is irradiated. The photodetector receives reflection light from the toner pattern or the surface material. The sensor light intensity control unit provides a control voltage to the light emitter and thereby controls light intensity of the light emitter. The density determining unit determines a toner density on the basis of output of the photodetector. Further, the density determining unit (a) determines as a correction parameter a first-order coefficient of the control voltage of the light emitter for an output voltage of the photodetector corresponding to reflection light from the surface material, (b) determines a correction amount corresponding to the correction parameter and the toner density, and (c) corrects the toner density on the basis of the correction amount.

An electrophotographic image forming apparatus for forming an image in accordance with image information includes: an image forming unit configured to form an image that is uniform in area percentage of each of primary colors and a secondary color on an intermediate transfer belt; a measurer configured to measure amounts corresponding to density distribution of residual toner left on the intermediate transfer belt, on which the image uniform in area percentage of each of the primary colors and the secondary color is formed and from which toner is transferred onto a recording medium, in the main-scanning direction; and a corrector configured to correct a tone value of the image information so as to reduce density nonuniformity of a streak region observed in the density distribution in the main-scanning direction using the amounts measured by the measurer.

An image forming apparatus includes an image forming device, an image density detector, and an output change device configured to cause the image forming device to form a test toner image while cyclically changing a charging power based on a charging change pattern and a developing bias based on a developing change pattern, generate an image density fluctuation pattern of the test toner image in a rotation direction of the latent image bearer, generate a writing change pattern to cyclically change a power of latent image writing based on the image density fluctuation pattern of the test toner image and one of the charging change pattern and a correlative pattern correlated with the charging change pattern. The output change device is configured to cyclically change the power of latent image writing based on the writing change pattern during image formation according to a user command.

An image forming apparatus includes an image forming unit configured to convey a recording medium and form an image on the recording medium based on an image forming condition; and a controller configured to control the image forming unit to form a test image and a scale image extending in a conveyance direction in which the recording medium is conveyed, obtain user instruction information related to a density fluctuation of the test image in the conveyance direction, and generate the image forming condition to suppress image density unevenness in the conveyance direction in an image to be formed by the image forming unit based on the user instruction information.