| 摘要 |
PROBLEM TO BE SOLVED: To determine an amount of remaining developer, taking account of an amount of developer existing near a developer carrier, by providing a linear member stretched near the developer carrier all the way from one end to the other end of the developer carrier in its axial direction and a tension detection means for detecting tension exerted on the linear member, and determining the amount of remaining developer based on the result of the detection by the tension detection means. SOLUTION: One end of a cord 18 is fixed to the internal wall of the side of a toner container 12. The cord 18 is disposed near the free end of and elastic blade over the long side of it. The cord 18 is passed through the internal-wall hole 12b of a toner container 12 and connected to a pressure sensor 19 with a ring 18a via a hook 19a, and a change in the tension of the cord 18 can be measured by the pressure sensor 19. Toner flow pressure exerted on the cord 18 is detected as the tension of the cord 18. Detecting the flow pressure of the circulation of the toner as the tension of the cord 18 disposed near a developing sleeve 6 in such a manner makes it possible to judge an amount of the toner remaining in the toner container 12. |
