| 摘要 |
PURPOSE:To prevent partial developer deficiency owing to comsumption by the unevenness of the developer caused by the change in original sizes by disposing a detecting element in the part where the developer consumption is largest, at the developer supply part of a developer vessel. CONSTITUTION:This device detects the residual amount of the developer in a developer vessel having an opening for supplying the developer to a developing roller 1 in the lower part by disposing a detecting element 33 near the opening of said vessel, wherein the element 33 is disposed near the part where the developer is supplied to the smallest size A6 out of the sizes A6-A3, A4 used in the width direction of the roller 1, and therefore, the residual amount of the developer may be detected in the position in the width direction where the developer consumption is highest, whereby the occurrence of development defects owing to partial developer deficiency is prevented. |
