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.

A transfer device includes an intermediate transfer belt having a surface to which a toner image may be transferred and solid lubricant particles are attached, a primary transfer member performing primary transfer of a toner image to the surface of the intermediate transfer belt, a secondary transfer member performing secondary transfer of the toner image to a surface of a recording medium, and a detection device detecting a density of the toner image and has a light irradiation unit irradiating the surface of the intermediate transfer belt and a light receiving unit receiving reflected light, in which a relationship between a volume-average particle size A (nm) of the solid lubricant particles attached to the surface of the intermediate transfer belt and a wavelength B (nm) of the light radiated from the light irradiation unit satisfies the following Expression:
Expression 1:B>A8.6+300.

An image forming apparatus includes first to third adjustment processing portions. The first adjustment processing portion adjusts an emission light amount of a light-emitting portion of a first sensor based on an electric signal output from a light-receiving portion of the first sensor and corresponding to regular reflection light reflected by a non-toner-adhering surface of an image-carrying member. The second adjustment processing portion adjusts an operation condition of an image forming portion based on a toner concentration of a first toner image in a specific color, that has a concentration smaller than a predetermined saturation concentration. The third adjustment processing portion adjusts an emission light amount of a light-emitting portion of a second sensor based on an electric signal output from a light-receiving portion of the second sensor and corresponding to diffuse reflection light reflected by a second toner image in the specific color, that has a predetermined reference concentration.

Provided is an image forming apparatus that reduces replacement frequency for waste toner container, and efficiently performs waste toner accommodation with a waste toner container. The image forming apparatus includes a toner detection sensor detecting a quantity of a toner in a toner container; a waste toner detection sensor detecting an accommodation quantity of a waste toner removed from a photosensitive medium and accommodated in a waste toner container; a waste toner container full-state forecasting part that, upon toner detection sensor detecting empty state of toner container, forecasts whether waste toner container is filled up with waste toner before toner container newly loaded is emptied, on detection result by waste toner detection sensor; and a system control part that, upon waste toner container full-state forecasting part forecasting waste toner container being filled up, notifies a replacement message urging replacement of waste toner container to a panel part.

An image forming apparatus determines, based on detection performed by an optical sensor unit on an intermediate transfer belt while light-emitting devices emit a predetermined amount of light, an amount of light the light-emitting devices emit when the optical sensor unit detects a misregistration detection toner pattern and a density variation detection toner pattern.

An image forming apparatus includes an image carrying member, a developing device, a cleaning unit and a processor. The developing device performs development with a developer containing a toner and a lubricant. The processor obtains information on a lubricant amount in the developing device; obtains, with respect to each section formed by dividing a surface of the image carrying member in a rotating shaft direction of the image carrying member, a partial coverage from electrostatic latent image writing information for a predetermined period about the section; sets, for the section having the partial coverage of a predetermined value or less, a developer supply amount for a patch to be formed outside an image forming region on the image carrying member, based on the above information; and causes the developing device to supply the set developer supply amount so that the patch is formed.

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.

The image forming apparatus includes an image processing section that converts image data into pixel data, an image forming section that forms a toner image based on the pixel data, and a fixing section that fixes the toner image to the recording material by heating the recording material with the toner image formed thereon while conveying the recording material through a nip portion, wherein the image processing section divides the pixel data corresponding to one recording material into a plurality of areas each formed of a predetermined number of pixels and acquires density information on some of the pixels within each of the areas as representative values, wherein the fixing section carries out a process of fixing the toner image for which the density information has been acquired, under a fixing condition according to a maximum value of the representative values.

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.

To prevent the detection accuracy from deteriorating due to stray light, an optical apparatus includes the following configuration. The optical apparatus includes a light-emitting member, a light-receiving member, and a substrate on which the light-emitting member and the light-receiving member are mounted. The substrate includes a plate-like substrate layer and a plate-like conductive layer. The optical apparatus further includes a light-shielding member disposed between the light-receiving member and the light-emitting member and inserted in a through-hole of the substrate provided between the light-receiving member and the light-emitting member. The light-receiving member receives reflected light from a portion to be irradiated with the light emitted from the light-emitting member. The conductive layer is excellent in light-shielding property compared to the substrate layer. The conductive layer is exposed to an inner cylindrical surface of the through-hole.