An optical detecting apparatus includes a substrate having a surface, on which a light emitter and a first light receiver are arranged, and a housing. The housing has a fixture surface, onto which the surface of the substrate is fixed, and an attachable surface on a side opposite to the fixture surface. The housing includes an emitted-light guiding path formed through the housing between the fixture surface and the attachable surface for light emitted from the light emitter to pass there-through and a first receiving-light guiding path formed through the housing between the fixture surface and the attachable surface for light to be received by the first light receiver to pass there-through. The housing includes an attachable portion formed on the attachable surface. The attachable portion protrudes in a direction to extend away from the substrate.

In an image forming apparatus, a length of a patch pattern from a first patch to a last patch included in the patch pattern is longer than a circumferential length that is a length of an intermediate transfer belt in a conveyance direction, an engine control unit forms patches included in a range within the circumferential length in a first density (low density), forms patches included in ranges beyond the circumferential length in a second density (high density) darker than the first density, from among the patches included in the patch pattern, and executes image adjustment control.

An image forming apparatus includes an image forming device, a gradation adjustment mark adder and a hardware processor. The hardware processor monitors and adjusts a gradation characteristic based on a result of scanning a gradation adjustment mark. The hardware processor makes a determination as to whether to form the gradation adjustment mark overlapping an image area of an image based on image data. If it is determined to form the gradation adjustment mark overlapping the image area, the hardware processor controls the gradation adjustment mark adder to add gradation adjustment mark information to the image data in the image area.

Disclosed is an image forming apparatus for forming an image on a sheet, the image forming apparatus including an image forming unit configured to form an image on a photosensitive member with the photosensitive member rotating, and transfer the image formed on the photosensitive member onto the sheet to form the image on the sheet, a reading unit configured to read a measurement image formed on the sheet by the image forming unit, the measurement image including a first detection image for detecting density at positions different in an axial direction of a rotation axis of the photosensitive member of an image to be formed on the photosensitive member; and a second detection image for detecting density at positions different in a rotation direction of the photosensitive member of an image to be formed on the photosensitive member.

Disclosed is an image forming apparatus configured to form an image on a sheet including an image forming unit configured to expose a photosensitive member with laser light, while the photosensitive member is rotating, to form an electrostatic latent image to develop the electrostatic latent image formed on the photosensitive member, a sensor configured to detect a pattern image formed by the image forming unit, and a controller configured to suppress density unevenness in a rotation direction of the photosensitive member of an image to be formed by the image forming unit, based on detection results which are obtained by the sensor and correspond to different positions of the pattern image in the rotation direction.

An image forming device includes a controller, an image former that causes a color material to adhere to a sheet for each of multiple pixels arranged in a first direction, and a sheet feeder that feeds the sheet in a second direction. The controller determines whether a first color material used for a first pixel out of the multiple pixels is identical to a second color material used for a second pixel adjacent to the first pixel on a training end side in the second direction with respect to the first pixel, and executes a correction process of correcting a density of the first color material when it is determined that the first color material is identical to the second color material, the density of the first color material is lower than a first density, and a density of the second color material is equal to or higher than a second density that is equal to or higher than the first density.

An image forming device includes: a photoreceptor drum; a developer that forms a toner image on the photoreceptor drum; a development-power supplier that supplies the developer with a developing bias; an image sensor that detects a density of a toner image; an environment sensor that detects a temperature and humidity; a replenisher that replenishes the developer with toner; and a controller that causes image-quality adjustment that changes the developing bias to be performed. The controller includes a storage that holds a replenishment condition in which timing at which the replenisher replenishes the toner is set, a correction value for the replenishment condition, and an ideal bias, and the controller corrects a correction value used until the next image-quality adjustment based on a bias difference that is a difference between an adjustment bias and the ideal bias, and a last correction value set in the last image-quality adjustment.

A method for forming a color correction pattern applied to an image forming device, where the image forming device includes a first image forming unit and a second image forming unit, and the first image forming unit and the second image forming unit are powered by the same power supply. The method includes controlling the first image forming unit to form a first-color correction pattern on an image carrier and controlling the second image forming unit to form a second-color correction pattern on the image carrier. The image carrier includes a first imaging area and a second imaging area disposed on two sides along a direction perpendicular to a carrier conveying direction respectively, where the first-color correction pattern is imaged in the first imaging area, and the second-color correction pattern is imaged in the second imaging area.

An optical detecting apparatus includes a substrate having a surface, on which a light emitter and a first light receiver are arranged, and a housing. The housing has a fixture surface, onto which the surface of the substrate is fixed, and an attachable surface on a side opposite to the fixture surface. The housing includes an emitted-light guiding path formed through the housing between the fixture surface and the attachable surface for light emitted from the light emitter to pass there-through and a first receiving-light guiding path formed through the housing between the fixture surface and the attachable surface for light to be received by the first light receiver to pass there-through. The housing includes an attachable portion formed on the attachable surface. The attachable portion protrudes in a direction to extend away from the substrate.

An image forming system includes an image forming section that prints an image on a recording medium and outputs the recording medium, a color measurement section that measures color of the image printed by the image forming section, an imaging unit that captures the image printed by the image forming section, and an analyzer that analyzes, based on the image captured by the imaging unit, whether or not the image subjected to color measurement by the color measurement section has an abnormality. When the analyzer determines that the image has an abnormality, the color measurement section does not output a color measurement result of the image having the abnormality.