Image Forming Apparatus

An image forming apparatus comprising:

• a carrier configured to convey a recording medium;
• a plurality of forming devices configured to form respective images at respective image forming positions on the recording medium, wherein the plurality of forming devices form a pattern on the carrier;
• a measuring device configured to measure the pattern formed on the carrier;
• and
• a correcting device configured to execute at least one of a steady-deviation detection and a varying-deviation detection with respect to the at least one of the plurality of forming devices and, on a basis of a result of the at least one of the steady-deviation detection and the varying-deviation detection, correct the image forming position of the at least of one of the plurality of forming devices,
• wherein:
• in execution of the steady-deviation detection, the correcting device controls the plurality of forming devices to form a first pattern, controls the measuring device to measure the first pattern, and detects a steady deviation amount of the image forming position on a basis of a measurement result of the first pattern by the measuring device;
• in execution of the varying-deviation detection, the correcting device controls at least one of the plurality of forming devices to form a second pattern, controls the measuring device to measure the second pattern, and detects a varying deviation amount of the image forming position on a basis of a measurement result of the second pattern by the measuring device, the varying deviation amount of the image forming position having a cycle;
• and
• the correcting device determines necessity of executing the other one of the steady-deviation detection and the varying-deviation detection on the basis of the measurement result of the measuring device in the one of the steady-deviation detection and the varying-deviation detection, and, upon determination that execution of the other one of the steady-deviation detection and the varying-deviation detection is necessary, executes the other one of the steady-deviation detection and the varying-deviation detection.