An image forming apparatus including a controller configured to switch between a first speed printing where a polygon mirror rotates at a first speed and laser light is at a first power and a second speed printing where the polygon mirror rotates at a second speed slower than the first speed and laser light is at a second power lower than the first power. The polygon mirror rotates at the first speed and laser light is at the first power when a first test pattern is formed. The polygon mirror rotates at the first speed and laser light is at the second power when a second test pattern is formed. The first speed printing is executed based on a detection result of the first test pattern. The second speed printing is executed based on a detection result of the second test pattern.

A transfer device includes: an endless member in an endless shape that orbits; primary transfer members that are respectively arranged on an opposite side of plural image holding bodies disposed side by side in a circumference direction of the endless member with the endless member interposed between the primary transfer member and the image holding body, and transfer an image held by the image holding body to the endless member; a secondary transfer member that transfers the image transferred to the endless member to a recording medium; an applying roll around which the endless member is wound, that is disposed on a downstream side of all the primary transfer members and on an upstream side of the secondary transfer member in the circumference direction, and that urges the endless member from an inner peripheral surface of the endless member to apply tension to the endless member; an upstream roll around which the endless member is wound, and that is disposed on the downstream side of all the primary transfer members and on an upstream side of the applying roll in the circumference direction; a contact and detachment member that moves at least some of the plural primary transfer members, and contacts and detaches the endless member and the image holding body to change a posture of the endless member; a detection member that faces a portion of the endless member between the upstream roll and the applying roll to detect the image transferred to the endless member; and a positioning mechanism that changes a posture of the detection member according to the change in the posture of the endless member to position the detection member at the endless member.

An image forming apparatus superimposes a plurality of color images each formed of a single-color developer to form a superimposed color image. The image forming apparatus includes a transfer belt and processing circuitry. The processing circuitry forms, as a correction pattern, combination patterns arranged along a conveyance direction of the color images and including a first pattern, a second pattern, and a third pattern. A formation interval of the first pattern constituting one combination pattern is shorter than a formation interval between one horizontal line of the first pattern constituting the one combination pattern and another horizontal line of the first pattern constituting another combination pattern. The one horizontal line is opposite the other horizontal line.

An apparatus and method for compensating for variation of the image placement for each color station in an intermediate transfer drum system. A sensor detects the image placed by the previous station and triggers the imaging on the drum such that it properly registered to the previous image. However, the variation of the drum’s radius results in runout which creates an error in the image placement, since the surface drum travel will be larger or smaller than expected. The method to correct for a lead edge offset for radial runout involves dividing the drum into regions and calculating an offset center of each region. As the drum transitions from region to region the offset value is updated to determine when to start imaging for proper placement on the sheet. The offset can be derived from the image runout to find the distance traveled from the transfer point or can be measured directly from color-to-color registration variation.

An image forming apparatus forms a color image on a recording medium by superimposing images of colors formed by image forming units. The apparatus includes a processor that: acquires a read image by reading the recording medium on which the color image has been formed; forms a register patch outside a job image forming region of the recording medium; and corrects image forming positions of the image forming units based on the read image that includes the register patch. The register patch includes: a leading end patch and a rear end patch formed with a reference color material; and one or more measurement target color patches formed with measurement target color materials between the leading end patch and the rear end patch. The hardware processor corrects the image forming positions based on relative positions of the leading end patch, the rear end patch, and the measurement target color patches.

A transfer device includes: an endless member in an endless shape that orbits; primary transfer members that are respectively arranged on an opposite side of plural image holding bodies disposed side by side in a circumference direction of the endless member with the endless member interposed between the primary transfer member and the image holding body, and transfer an image held by the image holding body to the endless member; a secondary transfer member that transfers the image transferred to the endless member to a recording medium; an applying roll around which the endless member is wound, that is disposed on a downstream side of all the primary transfer members and on an upstream side of the secondary transfer member in the circumference direction, and that urges the endless member from an inner peripheral surface of the endless member to apply tension to the endless member; an upstream roll around which the endless member is wound, and that is disposed on the downstream side of all the primary transfer members and on an upstream side of the applying roll in the circumference direction; a contact and detachment member that moves at least some of the plural primary transfer members, and contacts and detaches the endless member and the image holding body to change a posture of the endless member; a detection member that faces a portion of the endless member between the upstream roll and the applying roll to detect the image transferred to the endless member; and a positioning mechanism that changes a posture of the detection member according to the change in the posture of the endless member to position the detection member at the endless member.

An image forming apparatus and method for color registration are provided. The image forming apparatus according to an example includes a communication device to receive print data, a print engine including a plurality of photosensitive drums, and a processor to control the print engine to print the received print data on a plurality of printing papers, and to form a predetermined pattern for color registration in an inter-paper distance section between two of the plurality of printing papers on a paper feeding path.

An image forming apparatus includes an image forming device and circuitry. The image forming device forms an image with colorants of different colors. The circuitry determines whether there is a possibility that a shortage of a colorant adhesion amount occurs in primary-color image formation using a colorant of a primary color and cause the image forming device to perform two-color image formation in which only secondary-color image formation using a colorant of a secondary color different from the colorant of the primary color is added to the primary-color image formation using the colorant of the primary color to form an image to be formed with the colorant of the primary color, when the circuitry determines that there is a possibility that the shortage of the colorant adhesion amount occurs in the primary-color image formation using the colorant of the primary color.

An image forming apparatus superimposes a plurality of color images each formed of a single-color developer to form a superimposed color image. The image forming apparatus includes a transfer belt and processing circuitry. The processing circuitry forms, as a correction pattern, combination patterns arranged along a conveyance direction of the color images and including a first pattern, a second pattern, and a third pattern. A formation interval of the first pattern constituting one combination pattern is shorter than a formation interval between one horizontal line of the first pattern constituting the one combination pattern and another horizontal line of the first pattern constituting another combination pattern. The one horizontal line is opposite the other horizontal line.

A color management system for a printing system includes a fleet color management service that manages color calibration for printing devices. Calibration target print jobs are sent to the printing devices within a group. The calibration target print jobs are measured to capture color printing data. The measured data is uploaded to the fleet color management service, which determines color printing parameters for the group, including an aggregate maximum end point target. The fleet color management service generates a tone reproduction curve for all of the printing devices based on the color printing parameters. Validation of the color printing capabilities are performed using a validation set of the printing devices to determine the validation set printing devices can meet the aggregate maximum end point target.