| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device making the service life thereof possible to be easily and exactly judged. SOLUTION: In this developing device 1 equipped with a developing sleeve 4 facing opposite to an image carrier with a specified range, on respective periphery of butting rollers 5 and 6 disposed in order to maintain the above image carrier and the developing sleeve 4 with the specified range, respective groove (wear detecting means) 5a and 6a is provided thereon. In this case, since respective butting periphery on the butting roller 5 and 6 held in contact with the image carrier is gradually worn by the rotation thereof corresponding to the rotation of the image carrier, by confirming by the visual observation or measuring by a simple measuring tool with respect to the state of respective groove 5a and 6a formed on these butting periphery as wear detecting means, the developing sleeve 4 is made possible to easily and exactlly be predicted whether being used to the limit with no residual life, or possible to be used how long hereafter. |
