| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device capable of easily measuring the thickness of the resin layer of a developing roller and easily predicting the life of the developing roller in spite of simple constitution. SOLUTION: This image forming device is provided with the developing roller 26 whose outer peripheral surface is coated with a resin layer 28 and whose outside diameter including the layer 28 is formed to be nearly equal in dimension. Then, a tapered surface 27a inclined at a specified angle is formed near both ends of the roller 26 so that the thickness of the layer 28 may get thinner and thinner toward the respective ends in the image forming device. |
