| 摘要 |
PURPOSE:To prevent the drawbacks where electrical conductivity of a developer is lowered by mingling of foreign matter except the developer in the developer or the breakage of the developer itself and that the images formed on a recording medium are increasingly deteriorated by detecting the decrease in the electrical conductivity of the developer. CONSTITUTION:The image forming device which has the recording medium 5 for forming the images and a developing means for developing the images on the recording medium 5 and uses the developer repeatedly is provided with means 4, 6 for detecting the electrical conductivity of the developer and announcing means 18, 19 which announces the abnormality of the developer when the electrical conductivity detected by the detecting means 4, 6 is smaller than the prescribed value. The abnormality is thereby detected with the simple construction when the developer is deteriorated or runs short and, therefore, such inconvenience as image defect and image drop-out is prevented. |
