| 摘要 |
PURPOSE:To provide a simple, small, high-accuracy toner charge quantity measuring device by sucking a toner from the outside of a container together with air via a mesh filter, and measuring the toner charge quantity based on the opposite-polarity charges of a carrier left in the container. CONSTITUTION:A specimen two-constituent developer (a mixture of a carrier 2 and a toner 3) is put in a developer container 1, and a mesh filter 4 passing the toner 3 and not passing the carrier 2 is fitted to a cap 5. When an air suction pump is connected to an electric insulating fine pipe 6 kept in contact with the mesh filter 4 and the air is sucked in the arrow direction, the developer in the developer container 1 is sucked near to the mesh filter 4, and the toner 3 passes through the mesh filter 4 via the air current and discharged from the developer container 1. Charges having the same value and opposite polarity to the charges of toner 3 grains are accumulated in the electrostatic capacity between the developer container 1 and the ground, and they can be measured by an electrometer 7. |
