| 摘要 |
PURPOSE:To exactly detect the residual amt. of a toner and to maintain specified image quality by detecting a toner concn. at prescribed timing, comparing the toner concn. with the prescribed level of the next stage if this concn. is lower than the prescribed level and deciding whether the replenishment of the toner is necessary or not. CONSTITUTION:The toner concn. is detected at the prescribed timing by a toner concn. detecting sensor 13 provided below a developer transporting conveyor 12 and whether the toner is empty or not is detected by combining the number of the times when the concn. below the prescribed level is continuously detected and the decrease in the toner concn. to the prescribed next stage level. The toner is not immediately decided to be empty in the case the toner concn is decreased by the temporary failure in the replenishment of the toner by the solidification of the toner, etc. The pulverization of the toner by vibrations, etc., is then waited for. The toner concn. of the next stage level is assured and the image quality is maintained at a specified level even when the toner is detected to be empty. |
