A controller is configured to execute a larger gamut technology mode in which the controller performs image formation by controlling a ratio of a rotation speed of a development roller to a rotation speed of a photosensitive drum such that the ratio becomes a second speed ratio higher than a first speed ratio in a normal mode. The controller is configured to, when the controller executes the larger gamut technology mode, control transfer voltage based on a humidity around an image forming apparatus.

An image forming apparatus performs misregistration correction based on a detection result of a detection pattern. The detection pattern includes basic patterns arranged at a first interval in a sub-scanning direction. Each basic pattern includes N image groups arranged at a second interval. In the N image groups, a first group including an image at a first angle and a second group including an image at a second angle are arranged alternately in the sub-scanning direction. The first interval corresponds to a distance that a surface of an image carrier moves in a period of M times a first period corresponding to a rotation period of a rotational member, and the second interval corresponds to a distance that a surface of the image carrier moves in a period of 1/(N−1) of the first period.

An image forming apparatus supplies, to an image carrying member, a toner to which a lubricant is externally added to form a toner image and transfers the toner image to a sheet transported to the image carrying member. The image forming apparatus includes a control portion that controls, when a toner patch is formed onto the image carrying member in a part corresponding to a region between the sheets transported continuously, the drawing of the toner patch based on coverage information of the toner image transferred to the sheet transported in a predetermined period.

An image forming apparatus includes an image carrier that holds an image, which is formed by developing a latent image and which is transferred onto a recording medium, a developing device that is disposed adjacent to the image carrier and that develops the latent image, a light-reflection-type sensing unit that is disposed below the developing device in a vertical direction and that detects the image on the image carrier, and a guiding member that guides the recording medium, which is transported between the developing device and the sensing unit, and that covers an upper side of the sensing unit in the vertical direction in a state where a space is ensured on an optical path of the sensing unit.

Provided is an image forming apparatus having a simple configuration capable of measuring a toner current included in a developing current and accurately calculating a toner charge amount based on the measurement result. The developing device has a developer carrier that carries a two-component developer including a magnetic carrier and toner. The density detecting device detects the density of the toner image. The current detecting unit detects a DC component of a developing current that flows when a developing voltage is applied to the developer carrier. The control unit, in a state in which the image carrier is rotated at two or more different linear speeds during non-image formation, forms the same reference image on the image carrier by the developing device, and estimates the toner charge amount based on the developing current when the reference image is formed and the density of the reference image.

In a sensor, a light emitter outputs light with which a toner pattern on an image carrier or a surface material of the image carrier is irradiated, and a photodetector receives reflection light from the toner pattern or the surface material. The sensor light intensity control unit provides a control voltage to the light emitter and controls light intensity thereof. The density determining unit determines a toner density on the basis of output of the photodetector. Further, the density determining unit determines a reference control voltage of the light emitter to set as a predetermined value the output of the photodetector corresponding to the reflection light from the surface material, determines a correction parameter corresponding to the reference control voltage, determines a correction amount corresponding to the correction parameter and the toner density, and corrects the toner density on the basis of the correction amount.

A color measurement device includes a conveying roller unit that conveys a sheet in a conveying direction, a color sensor that is movable in a direction orthogonal to the conveying direction and measures a color of an image formed on the sheet, a white reference plate having a reference surface for measurement by the color sensor for calibration of the color sensor, lifting rollers that move with the color sensor and retain the sheet, and slid-on members that protrude to a level higher than the reference surface in a perpendicular direction to the reference surface. When the color sensor moves such that at least part of the lifting rollers overlaps the white reference plate as viewed from the perpendicular direction, the lifting rollers are brought into contact with the slid-on members, whereby a space is formed between the lifting rollers and the reference surface.

The present invention provides a recording medium detecting device, an image forming device, an image forming system, a recording medium detecting method, and a non-transitory recording medium storing a computer readable program capable of detecting a grain direction of a recording medium. A recording medium detecting device has: a sensor capable of detecting a recording medium from a first detection direction and a second detection direction different from the first detection direction; and a control unit. The control unit determines a grain direction of a recording medium from first surface property data obtained when the recording medium is detected from the first detection direction and second surface property data obtained when the recording medium is detected from the second detection direction.

In one example of the disclosure, a first sensor located adjacent to a first end of the blanket drum is utilized to take a first temperature reading. A second sensor located adjacent to a second end of the blanket drum is utilized to take a second temperature reading. A blanket creep condition is identified responsive to determining a difference in blanket drum temperatures is in excess of a predetermined threshold. A remedial measure is caused to be performed to address the blanket creep condition.

An image forming apparatus includes an image forming unit (LBP) to form an image on a sheet, a conveyance unit configured to convey the sheet, a sensor, which is configured to move in a direction perpendicular to a conveying direction in which the conveyance unit conveys the sheet, and to read the image on the sheet, and a controller. The image forming unit forms a first trigger image and a first pattern image on the sheet, and the image forming unit forms a second trigger image and a second pattern image at a position on the sheet different from a position of both the first trigger image and the first pattern image in the conveying direction. A formation area of the first trigger image in the direction perpendicular to the conveying direction overlaps with a formation area of the second pattern image.