| 摘要 |
PROBLEM TO BE SOLVED: To efficiently form a test image.SOLUTION: An image forming apparatus comprises an image forming unit which forms a plurality of test images for detecting unevenness in density, on one sheet, a signal output unit which outputs a detection signal of a reference position in a sub-scanning direction of a rotor for use as an image forming member in the image forming unit, and a control unit which detects a phase of a rotation period of the rotor on the basis of the detection signal output by the signal output unit (S3). The control unit determines a phase in which formation of each test image should be initiated in the rotation period (S2) so that density distributions in a certain number of periods can be obtained from the plurality of test images in all phases of the rotation period of the rotor, and formation of each test image is initiated at the timing when the phase of the rotation period of the rotor detected by the detection signal reaches the determined phase (S4).SELECTED DRAWING: Figure 4 |
