Abstract: Adjustment image data is for use in adjusting imaging operation. The adjustment image data is stored in a storage of an image forming apparatus and read from the storage to form an image on a sheet of paper at the time of adjusting an imaging operation of the image forming apparatus. The adjustment image data includes a single identification mark located in the vicinity of a longitudinal center of the sheet of paper.

Abstract: Adjustment image data is for use in adjusting imaging operation. The adjustment image data is stored in a storage of an image forming apparatus and read from the storage to form an image on a sheet of paper at the time of adjusting an imaging operation of the image forming apparatus. The adjustment image data includes a single identification mark located in the vicinity of a longitudinal center of the sheet of paper.

Abstract: An image forming apparatus includes a multi-color misalignment calculator that calculates an amount of multi-color misalignment of multiple color misalignment detection test pattern images based on position readings outputted by multiple test pattern image detectors, an image formation condition adjusting unit that adjusts an image formation condition of the image forming apparatus in accordance with the amount of multi-color misalignment of the multiple color misalignment detection test pattern images calculated by the multi-color misalignment calculator, and a process control unit that initiates a first multi-color misalignment correction control mode including a skew misalignment correction process and a second multi-color misalignment correction control mode excluding the skew misalignment correction process to correct multi-color misalignment of the multiple color misalignment detection test pattern images.

Abstract: An image forming apparatus includes a multi-color misalignment calculator that calculates an amount of multi-color misalignment of multiple color misalignment detection test pattern images based on position readings outputted by multiple test pattern image detectors, an image formation condition adjusting unit that adjusts an image formation condition of the image forming apparatus in accordance with the amount of multi-color misalignment of the multiple color misalignment detection test pattern images calculated by the multi-color misalignment calculator, and a process control unit that initiates a first multi-color misalignment correction control mode including a skew misalignment correction process and a second multi-color misalignment correction control mode excluding the skew misalignment correction process to correct multi-color misalignment of the multiple color misalignment detection test pattern images.

Abstract: An image forming apparatus includes an image bearing member, a plurality of developing devices, a transfer device, a moving device, a color drift detector, a test pattern forming device, and a color drift correction device. The test pattern forming device forms a test pattern on the image bearing member. The color drift correction device corrects the color drift in a separating state in which the image bearing member and the transfer device are separated from each other. The test pattern forming device forms the test pattern again in an area on the image bearing member contacting the transfer device but not pressed by the transfer device after the color drift correction device corrects the color drift in the separating state, and the color drift correction device corrects the color drift in the contact state in which the image bearing member and the transfer device are in contact with each other.

Abstract: An image forming apparatus includes an image bearing member, a plurality of developing devices, a transfer device, a moving device, a color drift detector, a test pattern forming device, and a color drift correction device. The test pattern forming device forms a test pattern on the image bearing member. The color drift correction device corrects the color drift in a separating state in which the image bearing member and the transfer device are separated from each other. The test pattern forming device forms the test pattern again in an area on the image bearing member contacting the transfer device but not pressed by the transfer device after the color drift correction device corrects the color drift in the separating state, and the color drift correction device corrects the color drift in the contact state in which the image bearing member and the transfer device are in contact with each other.

Abstract: A drive unit for rotating a first rotary member and a second rotary member disposed around the first rotary member includes a drive source, an output gear driven by the drive source, a first gear greater in diameter than the output gear and configured to engage the output gear, a first joint member projecting from the first gear coaxially and coupled to the first rotary member, a second gear smaller in diameter than the first gear and connected between the first gear and the first joint member, a driven gear smaller in diameter than the first gear and disposed within an area of the first gear in a radial direction thereof to engage the second gear to be driven thereby, and a second joint member projecting from the driven gear coaxially and connected to the second rotary member.

Abstract: A drive unit for rotating a first rotary member and a second rotary member disposed around the first rotary member includes a drive source, an output gear driven by the drive source, a first gear greater in diameter than the output gear and configured to engage the output gear, a first joint member projecting from the first gear coaxially and coupled to the first rotary member, a second gear smaller in diameter than the first gear and connected between the first gear and the first joint member, a driven gear smaller in diameter than the first gear and disposed within an area of the first gear in a radial direction thereof to engage the second gear to be driven thereby, and a second joint member projecting from the driven gear coaxially and connected to the second rotary member.