A measurement device is provided with: a measurement unit including a first mode that measures an electrical resistance of a recording medium used in an image forming apparatus in a first predetermined range of electrical resistance values and a second mode that measures the electrical resistance in a second range of electrical resistance values different from the first range, the second range and the first range being set such that with respect to the electrical resistance of multiple brands of recording media, a number of brands belonging to the second range is greater than a number of brands belonging to the first range; and a control unit that controls the measurement unit to prioritize execution of the second mode over the first mode.

An image forming apparatus includes a converter configured to convert image data with use of a tone correction condition corresponding to a position in a main scanning direction of the image data, and an image forming unit, which includes a photosensitive member and an exposure portion configured to expose the photosensitive member to light based on the converted image data, and is configured to form an image on a recording medium. The image forming apparatus further includes a holding portion configured to hold a plurality of feedback conditions corresponding to a plurality of tones and a controller configured to control the image forming unit to form a plurality of test images, acquire measurement results for the plurality of test images, and generate the tone correction condition based on the measurement results and the plurality of feedback conditions.

An apparatus comprising a first control unit that executes density correction processing on image data and generates an image signal, an image forming unit that forms an image on a recording medium on the basis of the image signal, and a second control unit that controls the image forming unit. The first control unit includes a specifying unit that transmits specifying information relating to the density correction processing to the second control unit. The second control unit includes an acquisition unit that acquires a parameter relating to the image forming apparatus, and an estimation unit that estimates a plurality of image densities corresponding to tone levels identified by the specifying information transmitted from the first control unit on the basis of the parameter acquired by the acquisition unit and transmits the plurality of image densities to the first control unit.

A photocuring printing system. A developing drum is rotatable and is light-transmissive; the developing drum and a carrier are oppositely arranged and movable with respect to each other; the developing drum has a developing surface on which an electrostatic latent image is formed by the developing engine; a feeder and the developing surface are oppositely arranged; during a rotation of the developing drum, a photocurable material provided by the feeder is selectively attracted by the electrostatic latent image to form a material layer on the developing surface; the material layer is applied, by the developing drum, on a forming surface of the carrier or a cured model on the carrier; and a curing light beam emitted by a curing light source passes through a material-laying side of the developing drum to irradiate the material layer between the developing drum and the carrier to form a cured layer.

An image forming apparatus includes a sheet separation device, a first sheet feeder, a second sheet feeder, an image forming device, and circuitry. The sheet separation device is configured to separate a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet. The first sheet feeder is configured to feed the two-ply sheet. The second sheet feeder is configured to feed an inner sheet to be inserted between the two sheets. The image forming device is configured to form an image on a surface of the inner sheet. The circuitry is configured to cause the first sheet feeder to feed the two-ply sheet, perform a sheet separating operation on the two-ply sheet and cause the second sheet feeder to start feeding the inner sheet before completion of the sheet separating operation on the two-ply sheet.

A developing cartridge may include: a casing for accommodating developer therein; a developing roller rotatable about an axis extending in a first direction and positioned at one side of the casing in a second direction; a storage medium having an electric contact surface; and a holder movable relative to the casing in the second direction with the electric contact surface between a first position and a second position, the holder having an outer surface at which the electric contact surface is positioned.

A controller is configured to control a print engine and a conveyor to form an image on both sides of a sheet. The controller is configured to: in a case where images to be formed on both sides of each of an Nth (N is a positive integer) sheet, an (N+1)th sheet, and an (N+2)th sheet are all monochrome image or all color image, convey the (N+2)th sheet to the print engine and form an image before forming an image on both sides of the (N+1)th sheet; and in a case where the images to be formed on both sides of each of the Nth sheet, the (N+1)th sheet, and the (N+2)th sheet are a mixture of the monochrome image and the color image, convey the (N+2)th sheet to the print engine and form an image after forming an image on both sides of the (N+1)th sheet.

A rotating force transmitting part for an electrophotographic photosensitive drum for a main assembly of the electrophotographic image forming apparatus, wherein the main assembly of the electrophotographic image forming apparatus includes a driving shaft, to be driven by a motor, having the rotating force applying portion, and wherein the electrophotographic photosensitive drum is dismountable from the main assembly of the electrophotographic image forming apparatus in a direction substantial perpendicular with an axial direction of the driving shaft, the rotating force transmitting part includes a coupling member engageable with the rotational force applying portion to receive a rotational force for rotating the electrophotographic photosensitive drum in the state in which electrophotographic photosensitive drum is mounted to the main assembly of the electrophotographic image forming apparatus, wherein the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the electrophotographic photosensitive drum to the electrophotographic photosensitive drum and a disengaging angular position in which the coupling member is inclined away from the axis of the electrophotographic photosensitive drum from the rotational force transmitting angular position, wherein when the process cartridge is dismounted from the main assembly of the electrophotographic image forming apparatus in a direction substantially perpendicular to the axis of the electrophotographic photosensitive drum, the coupling member moves from the rotational force transmitting angular position to the disengaging angular position.

The image forming apparatus includes a drum cartridge having a photosensitive drum and a drum drive input member; a developing cartridge configured to be movably mounted to the drum cartridge, the developing cartridge comprising a developing roller disposed so as to face the photosensitive drum and a developing drive input member; a drum drive transmission member configured to engage with the drum drive input member and configured to transmit drum driving force to the drum drive input member while permitting a positional gap of the drum drive input member within a predetermined range; and a developing drive transmission member configured to engage with the developing drive input member and configured to transmit developing driving force to the developing drive input member while permitting a positional gap of the developing drive input member within a predetermined range.

A mechanism that makes it possible to output a saddle-stitched brochure in a correct page order when a post-processing apparatus that executes a saddle-stitching process by switching back a sheet is caused to execute the saddle-stitching process. Sheets discharged from a printing apparatus are switched back by reverse rotation of a conveying roller pair, and are conveyed into a conveying path for a saddle-stitch bookbinding process. The sheets are accumulated in an accumulation tray for the saddle-stitch bookbinding process. When the saddle-stitch bookbinding process is caused to be executed on the accumulated sheets by the post-processing apparatus, the order of image formation is decided such that the order of pages of images printed on the saddle-stitched sheets becomes correct. The images are printed on the sheets in the decided order of image formation.