| 摘要 |
PURPOSE:To improve image quality by preventing an image from being deteriorated even when the characteristic of developer and toner is changed. CONSTITUTION:This device is provided with a toner amount measuring means 9 for measuring the adhesive amount of the toner on a photosensitive body 8, a variable means 45 which varies magnetic flux density on a developing roller 1, and a control means 10 for controlling the variable amount of the magnetic flux density based on the adhesive amount of the toner. Developing density on the photosensitive body 8 is measured by the means 9. When it is sparse, the magnetic flux density on the roller 1 is made small by the means 45 to increase the outflow of the developer 7, and when it is dense, the magnetic flux density is made large to decrease the outflow of the developer 7, so that image density is stabilized. |
