| 摘要 |
PURPOSE:To present an improved device, by applying constant potential to one side and equipotential to the other side of two pairs of conductive surface disposed in a developer passage, measuring the quantity of deposited toner, comparing and operating each measured value and comparing with the reference value. CONSTITUTION:The developer flows downward in the arrow direction within a passage. When a switch 15 is made to the positive pole of a power source 14, an electric field is created between counter and detecting electrodes 5, 7, and the toner in the developer is attracted to either electrode. Reflecting the electrode 7 from a light source 9 due to deposit of toner, the quantity of reduced light to a photo detector 11 is converted into an electrical signal by the detector 11, and is inputted into a comparative arithmetic circuit 13. The other pair of counter and detecting electrodes 6,8 is connected to the negative pole side of the power source 14 to be set at the same potential. When the electric field is zero, the quantity of deposited toner is measured by the light source 10 and photo detector 12, and the measurement is converted into electrical signal by the detector 12 to be inputted into the circuit 13. Subtracting the toner deposit quantity on the electrode 8 side from that on the electrode 7 side and correcting to obtain true developing capacity, the corrected value is operated in the circuit 13 and compared with the reference value, so that the accurate developing capacity may be measured. |
