| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high-quality image without a toner discharge trace, a previous image ghost, etc., by preventing the violent discharge of toner from the contact part of a supplying roller with a developing sleeve and further, a failure in peeling the toner remaining on the developing sleeve. SOLUTION: The elastic layer 7b of the supplying roller is formed to obtain two-layer structure of an inner layer B and a front layer A thereon and the number of cells 18 for each of the inner and front layers B and A is >=50 pieces/ inch. For making the quantity of the toner absorbed into the elastic layer 7b smaller, the number of the cells is made larger in the inner layer B and for reducing the discharge of the toner from the elastic layer, the number of the cells is decreased in the front layer A, so that the difference in the number of the cells between the inner and front layers B and A is >=5 pieces/inch. The thickness of the front layer A is set to be 3 mm, that is, two times the encroaching amount of the supplying roller in its contact part with the developing sleeve. |
