| 摘要 |
PURPOSE:To detect the ratios of the toner in the developer readily with less change with time by placing the developer composed of toner and carrier on a conductor applied with voltage to a fixed thickness and measuring its electric field by a non- contact type electrometer. CONSTITUTION:The developer 4 composed of toner and carrier is placed on a conductive conveyor 1 and is conveyed. It is put to a fixed thickness by the height control plate 5 provided on the way. The probe 6 of a noncontact type electrometer which opposes to the conveyor 1 measures the electric field by the conveyor 1 to which reference voltage VS is applied through the developer 4 of a fixed thickness. Since the toner and carrier constituting the developer 4 differ in dielectric constant, the potential value measured by the probe 6 varies with the mixing ratios of the toner. Hence, the toner concentration in the developer passing under the probe may be detected with less change with time by the simple constitution. |
