| 摘要 |
PURPOSE:To eliminate an expensive toner residual sensor by providing a toner concentration sensor, integrating a value corresponding to the rotating speed of a toner discharge roller when toner volume in a developing tray is below a prescribed value and outputting a warning signal when the integrated value reaches the prescribed value. CONSTITUTION:The title machine is provided with a controller 37 which, when the volume of the toner 8 in the developing tray 12 is below the prescribed value, rotates the toner discharge roller 14, and whereas when the toner volume in the developing tray 12 is restored to the prescribed value, stops the rotation of the toner discharge roller 14. The controller 37 integrates numerics corresponding to the rotating speed of the toner discharge roller 14, and when the value reaches the prescribed one, outputs the warning signal. By utilizing the fact that a roughly constant amount of toner 8 is discharged from a toner hopper 9 in response to the rotation of the toner discharge roller 14, the controller warns that the toner in the toner hopper becomes less. Thus, an expensive toner residual sensor is not needed to attain the inexpensive machine. |
