| 摘要 |
PROBLEM TO BE SOLVED: To correctly calculate the amount of displacement of a toner image, without increasing the cost or the labor. SOLUTION: A polarization mirror 293 is disposed at an angle, where light is not made incident to a first light-receiving element 291 and a second light-receiving element 292, at the same time. A storage section stores, as a reference phase difference, the phase differenceΔT0 between detection signals S1 and S2 output from the first light receiving element 291 and the second light-receiving element 292 at the reference position of an intermediate transfer belt 271. Thereafter, a phase differenceΔT1 between the present detection signals S1 and S2 output, when light is emitted to a toner patch 61, formed at any position other than the reference position is measured. Then, a displacement calculating section corrects the amount of displacement calculated, having the difference between the reference phase differenceΔT0 and the present phase differenceΔT1, as a change in the distance between the intermediate transfer belt 271 and the polarization mirror 293, and thereby, the displacement calculating section cancels the measurement errors due to the distance change amount. COPYRIGHT: (C)2010,JPO&INPIT |
