| 摘要 |
PURPOSE:To obtain an image having always stable density without being affected by environment by detecting the humidity of the environment surrounding a developer and controlling the electrostatic charge on the developer according to the detected humidity. CONSTITUTION:The decrease in image density agree well with the increase in the quantity of the electrostatic charge in a toner. The density of the image decreases as the quantity of the electrostatic charge in the toner increases. The number of revolution of a roller 16 for feeding an electrostatic charge controlling agent 15a disposed in a vessel 15 contg. said agent is there upon controlled according to the output of a humidity sensor 14 disposed in a developing vessel 4a. The roller 16 is rotated by a driving motor, by which the agent 15 is dropped onto a conveying screw 13. Said agent is conveyed into the vessel 4a by the revolution of the screw 13. |
