As shown in a variation shown in FI

As shown in a variation shown in FIG. 7, the biasing member 80 may be disposed such that the central axis line TL passes through a side end of the biasing member 80. It is sufficient that the center of the cleaning roller shaft 60a is on the central axis line TL while the biasing force of the biasing member 80 is applied to the cleaning roller 60. In other words, when the central axis line TL passes through the biasing member 80 so as to be parallel with the biasing direction, it can be considered that the biasing direction of the biasing member 80 is on the same line as the central axis line TL. The load from biasing member 80 may be adjusted by the bearing part 70 so as to be applied to the charging roller shaft 50a and the cleaning roller shaft 60a.