An image forming system includes: a first image forming apparatus including a first fixer that fixes an image formed on a recording medium to the recording medium; a second image forming apparatus including a second fixer that fixes an image formed on the recording medium to the recording medium, the second image forming apparatus being connected to a downstream side of the first image forming apparatus in a transport direction of the recording medium; and a hardware processor that determines first transport control content in which the recording medium is transported in the first image forming apparatus and the second image forming apparatus, and sets second transport control content so that the recording medium that has been processed by the first fixer is processed in a different position by the second fixer.

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.

Provided are an image bearing member; a charging member that charges the image bearing member; an exposure unit that exposes the image bearing member; a developing unit that develops an electrostatic latent image as a developer image by supplying a developer, charged to regular polarity, to the image bearing member; a transfer member that transfers the developer image to a transfer-receiving body; and a collecting member that collects a deposit on the image bearing member downstream of a transfer portion of the image bearing member at which the developer image is transferred to the transfer-receiving body by the transfer member, and upstream of a charging portion of the image bearing member charged by the charging member, in a rotation direction of the image bearing member. After transfer of the developer image to the transfer-receiving body, the developer remaining on the image bearing member is collected by the developing unit.

An endless belt includes a base material layer containing a polymer material and conductive particles, wherein, in an image obtained by observing a cross section taken along a thickness direction of the base material layer with an atomic force microscope, a proportion of a total area Ap of cross sections of all the conductive particles is 9.0% or more and 14.5% or less with respect to a total cross-sectional area At of the base material layer, and a proportion of a total area Ab of cross sections of conductive particles having an area of 0.01 .Math.m.sup.2 or more among cross sections of the conductive particles is 28.0% or more and 65.0% or less with respect to the total area Ap of cross sections of all the conductive particles.

An image forming apparatus includes a conveyance unit that conveys a recording medium in contact with one surface of the recording medium along a conveyance path; a first image forming group that is provided on the other surface side of the recording medium in the conveyance path, and includes plural image forming sections that form a toner image; a second image forming group that is provided on a downstream side in a conveyance direction of the first image forming group on the other surface side of the recording medium in the conveyance path, and includes plural image forming sections that form a toner image; a first intermediate transfer body that is provided on the downstream side in the conveyance direction of the first image forming group, and to which the toner image formed by the plural image forming sections of the first image forming group is primarily transferred; a second intermediate transfer body that is provided on an upstream side in the conveyance direction of the second image forming group, and to which the toner image formed by the plural image forming sections of the second image forming group is primarily transferred; a first transfer unit that secondarily transfers the toner image from the first intermediate transfer body to the other surface of the recording medium conveyed by the conveyance unit; and a second transfer unit that secondarily transfers the toner image from the second intermediate transfer body to the other surface of the recording medium conveyed by the conveyance unit.

An image forming apparatus includes: a toner image former that forms a toner image on an outer peripheral surface of a photosensitive rotating body and that transfers the toner image having been formed onto a transfer receiving object; a detector that detects a grayscale abnormality of the toner image on the photosensitive rotating body or the transfer receiving object; a cleaner that cleans the outer peripheral surface of the photosensitive rotating body; and a hardware processor that causes the cleaner to clean when the detector detects the grayscale abnormality at a same position in a main scanning direction per circumferential length of the photosensitive rotating body in a sub-scanning direction.

An endless belt includes a resin, and particles having an average primary particle diameter of 8 nm or more and 20 nm or less. In a volume frequency distribution of the particles determined by small-angle X-ray scattering measurement, the ratio (area B/area A) of graph area B of a particle diameter region of over 35 nm to graph area A of a particle diameter region of 35 nm or less is 0.3 or less.

An image forming apparatus includes a transfer portion, a fixing unit, a conveyance belt configured to convey a sheet from the transfer portion toward the fixing unit, a driving portion configured to drive the conveyance belt, and a controller configured to control the driving portion. The controller is configured to, in a case of switching the image forming apparatus to a standby state in which the image forming apparatus is ready to start an image forming operation and stands by for input of an image forming job, execute preheating in which the fixing unit is preliminarily heated, and cause the driving portion to rotate the conveyance belt while the preheating is executed.

An image forming apparatus includes: a circulating member that is a part of a transport path that transports a recording medium; a holding member that is fixed to the circulating member, circulates, and holds a leading end portion of the recording medium; an image forming section that forms an image on the recording medium at an image forming position in a circulation path of the circulating member; and a feeding section that feeds out the recording medium to a holding position where the holding member holds the leading end portion of the recording medium. When a circulation velocity Vg is defined as a velocity at which the circulating member circulates the holding member, a transport velocity of the recording medium is reduced from a first transport velocity V1, which is higher than the circulation velocity Vg, to a second transport velocity V2, which is lower than the first transport velocity V1, before the leading end portion of the recording medium enters the holding position.

An image forming apparatus includes an optical sensor configured to detect an image formed on an intermediate transfer belt. The optical sensor includes a first LED, a second LED, a first PD, and a second PD on a substrate. The first PD is arranged at a position at which specularly reflected light of light emitted from the first LED can be received, and scattered reflected light of light emitted from the second LED can be received. The second PD is arranged at a position at which scattered reflected light of light emitted from the second LED can be received. A light receiving surface of the first PD and a light receiving surface of the second PD are formed at different angles. The light receiving surface of the first PD has an area that is smaller than an area of the light receiving surface of the second PD.