Image forming device, non-transitory computer readable recording medium storing image forming program, image forming method, and image forming system

An image forming method executed by an image forming device configured to form toner images on corresponding photosensitive bodies, and configured to perform primary transfers for transferring the toner images on the corresponding photosensitive bodies onto an intermediate transfer body and to perform a secondary transfer for transferring the toner images from the intermediate transfer body onto a recording medium;

• wherein the image forming device includes
• a position correction unit configured to cause plural toner image forming units to form predetermined patterns and configured to correct forming positions of the toner images by the corresponding toner image forming units in a direction parallel to a rotation axis of the intermediate transfer body, based on information about spacing among the patterns, the spacing among the patterns being read by a pattern reading unit,
• wherein the image forming method comprises:
• a position detection step of detecting a position of the intermediate transfer body in the direction parallel to the rotation axis of the intermediate transfer body, the position detection step being executed by a position detection unit;
• a position control step of controlling movement of the intermediate transfer body such that, when the intermediate transfer body is moved in the direction parallel to the rotation axis of the intermediate transfer body to a target position, the position control step causes the intermediate transfer body to move to the target position at a constant speed at least during a part of a first time interval, the movement of the intermediate transfer body being controlled by the position control step during the first time interval;
• a speed determination step of determining whether a speed of the intermediate transfer body in the direction parallel to the rotation axis of the intermediate transfer body is stabilized, based on a time variation of information about the position of the intermediate transfer body detected by the position detection unit, the speed determination step being executed by a speed determination unit;
• and
• an image forming control step of causing the plural toner image forming units to form the corresponding toner images, causing the image forming device to perform corresponding primary transfers, or causing the image forming device to perform a secondary transfer, during a second time interval in which the intermediate transfer body is moving in the direction parallel to the rotation axis of the intermediate transfer body at the constant speed, after causing the position correction unit to correct the forming positions of the toner images, the image forming control step being executed by an image forming control unit.

An image forming system comprising at least an image forming device,

• wherein the image forming device is configured to form toner images on corresponding photosensitive bodies, and configured to perform primary transfers for transferring the toner images on the corresponding photosensitive bodies onto an intermediate transfer body and to perform a secondary transfer for transferring the toner images from the intermediate transfer body onto a recording medium,
• wherein the image forming device includes
• a position detection unit configured to detect a position of the intermediate transfer body in a direction parallel to a rotation axis of the intermediate transfer body;
• and
• a position control unit configured to control movement of the intermediate transfer body, wherein, when the position control unit controls the movement of the intermediate transfer body so that the intermediate transfer body is moved in the direction parallel to the rotation axis to a target position, the position control unit causes the intermediate transfer body to move to the target position at a constant speed, at least during a part of a first time interval, the movement of the intermediate transfer body being controlled by the position control unit during the first time interval;
• wherein the image forming system includes
• a position correction unit configured to cause plural toner image forming units to form predetermined patterns and configured to correct forming positions of the toner images by the corresponding toner image forming units in a direction parallel to the rotation axis of the intermediate transfer body, based on information about spacing among the patterns, the spacing among the patterns being read by a pattern reading unit;
• a speed determination unit configured to determine whether a speed of the intermediate transfer body in the direction parallel to the rotation axis of the intermediate transfer body is stabilized, based on a time variation of the position of the intermediate transfer body detected by the position detection unit;
• and
• an image forming control unit configured to cause the plural toner image forming units to form the corresponding toner images, to cause the image forming device to perform corresponding primary transfers, or to cause the image forming device to perform a secondary transfer, when the speed determination unit determines that the speed of the intermediate transfer body in the direction parallel to the rotation axis of the intermediate transfer body is stabilized, after causing the position correction unit to correct the forming positions of the toner images.