| 摘要 |
PROBLEM TO BE SOLVED: To try not to be affected by uneven reading, when correcting the image formation density unevenness by reading a test chart by means of a scanner.SOLUTION: With regard to a two-dimensional test chart where an image is formed so that the density is constant in the first output direction but different in the second output direction, by repeating image formation in the first output direction in the second output direction on a sheet, a reading section executes first reading of the test chart while aligning the first output direction and second reading direction, and then executes second reading for reading while aligning the first output direction and second reading direction after rotating the read test chart by 180 degrees. Image formation density unevenness of the test chart in the first output direction is detected using first reading results and second reading results in a state rotated by 180 degrees relatively.SELECTED DRAWING: Figure 1 |
