An image forming apparatus includes an image carrying member, a charging device, a charging voltage power supply, an exposure device, a development device, a development voltage power supply, an intermediate transfer member, a primary transfer member, a secondary transfer member, a transfer voltage power supply and a control unit. The development device includes a developer carrying member which carries a developer containing a toner. The development voltage power supply applies, to the developer carrying member, a development voltage in which an alternating-current voltage is superimposed on a direct-current voltage. The transfer voltage power supply applies a transfer voltage to the primary transfer member and the secondary transfer member. The control unit performs a first image quality improvement mode in which the frequency of the alternating-current voltage of the development voltage and a primary transfer current flowing between the image carrying member and the primary transfer member are simultaneously changed.

An image forming system includes an image forming apparatus, a varnish applying apparatus, an input unit, a first image processing unit, and a second image processing unit. The image forming apparatus forms a toner image on a recording material on the basis of image data obtained by subjecting first image data to data change processing. The varnish applying apparatus forms a varnish image on the recording material on the basis of image data obtained by subjecting second image data to the data change processing.

An image forming apparatus includes a platen on which an original is to be placed, a feeder configured to feed an original placed on a tray, a sensor configured to detect a sheet on the tray, a lamp provided to the feeder, a reader configured to read the original placed on the platen and to read the original conveyed by the feeder, an image forming unit configured to form an image on a sheet, and a controller. The controller is configured to control the image forming unit to form a first test image on a sheet, control the reader to read the first test image formed on the sheet placed on the platen, control a density of the image to be formed by the image forming unit based on a reading result of the first test image.

An image forming apparatus includes a rotatable image bearer, a toner image forming device, an image reader, and a control unit. The toner image forming device forms a test toner image on the image bearer. The image reader reads the test toner image and a predetermined reference member. The control unit calculates an amount of toner contained in the test toner image based on image data from the test toner image. Based on image data from the reference member, the control unit selects a position of a pixel to be used for calculation of the amount of toner contained in the test toner image from pixels included in the image data from the reference member, to calculate the amount of toner contained in the test toner image from data of a pixel located at the position thus selected among pixels included in the image data from the test toner image.

An image forming apparatus which forms an image on a medium on the basis of an input image signal includes: an image carrier configured to carry a developed toner image transferred to the medium on a photoreceptor layer; a contact member arranged so as to be in contact with the surface of the photoreceptor layer; a trace pattern generating unit configured to generate a trace pattern indicating specific information on the image forming apparatus; a composition unit configured to add the trace pattern to the image signal; and an acquiring unit configured to acquire information on the thickness of the photoreceptor layer of the image carrier, wherein the trace pattern is used for arranging a plurality of image areas at respective positions, and the trace pattern generating unit is configured to generate the trace pattern with the image area whose size is reduced in accordance with reduction of the thickness of the photoreceptor layer.

An image forming apparatus includes a fixing device configured to include a pressure section and a heating section for heating an image receiving medium and to execute a fixing processing for fixing an image formed on the image receiving medium with a decolorable color material at a fixing temperature or an erasure processing for erasing an image at a decoloring temperature, a reading section configured to be arranged at the upstream side of the fixing device in the conveyance direction of the image receiving medium to read an identifier indicating whether or not the color material of the image formed on the image receiving medium can be decolorized, and a control section configured to control the execution of the erasure processing of the image on the image receiving medium with the fixing device according to a result of reading of the identifier with the reading section.

A control device includes an image-formation command section and a first reception section. The image-formation command section commands an image forming section to form multiple latent images based on one input image onto an image bearing member in accordance with different light emission patterns by using a light source including multiple light emitting members, develop the latent images, and output the multiple developed images to a medium. The first reception section receives a designation by a user with respect to one of the multiple light emission patterns after the multiple images are output. Each light emission pattern indicates which of the multiple light emitting members included in the light source is to emit light.

An image forming apparatus includes a photosensitive member having first and second areas at different positions at an axial end of the photosensitive member, the first and second areas not overlapping an image area in an axial direction of the photosensitive member; a detecting unit that detects an image; and a forming unit that forms a transfer-object image in the image area, the transfer-object image being transferred to a transfer area of continuous-form paper, the forming unit further forming first and second images in the first and second areas of the photosensitive member, respectively, the first image not being transferred to the transfer area but being detected by the detecting unit for use in an operation of controlling conditions for image formation, the second image not being transferred to the transfer area and not being used in the operation of controlling the conditions for image formation.

An image forming apparatus includes: an output unit configured to receive light reflected from a measurement image on an image carrier and output a signal corresponding to a light receiving result; a detection unit configured to detect a temperature of the output unit; a conversion unit configured to convert an output value output from the output unit, based on a conversion condition; a controller configured to control an image forming condition for adjusting a density of an image to be formed based on a converted output value by the conversion unit; and a generation unit configured to, at a predetermined timing, acquire an output value output from the output unit without emitting light, control the detection unit to detect the temperature, and generate the conversion condition based on the acquired output value and the detected temperature.

An image forming apparatus includes a photosensitive member that includes a photosensitive layer, the photosensitive layer being thicker at a first axial end of the photosensitive member than at a second axial end of the photosensitive member; and a forming unit that forms a first image and a second image on the photosensitive member, the first image being transferred to each of transfer areas defined on continuous-form paper, the second image being transferred to the first axial end but to neither a position between adjacent ones of the transfer areas that are side by side in a longitudinal direction of the continuous-form paper nor a position in any of the transfer areas.