| 摘要 |
PURPOSE: To provide a developing device capable of obtaining an image improved in uniformity, especially a uniform solid image without solid streaks by development with toner of a one-component developer. CONSTITUTION: The developing device is constituted to provide a developing sleeve 110 carrying the toner of the one-component developer and rotated to carry the toner to a developing region facing a photoreceptor drum, a supplying roller 112 of a foamed body rotated in contact with the sleeve 110, to supply the toner to the sleeve 110 and a regulating blade 113 abutted on the sleeve 110, to regulate the layer thickness of the toner on the sleeve. The flowability index (a) (%) of the toner and the number of foamed cells (b) (piece/25mm) of the foamed body of the supplying roller 112 satisfy the relation of 90-b<=a<=110-b. Thus, the number of the foamed cells of the supplying roller 112 can be optimized with respect to the flowability of the toner, the solid streaks, that is, the streaky density unevenness of the solid image, which is conspicuously generated when the toner excellent in the flowability is used can be prevented and the void of the image caused by a deficiency of the supplying of the toner can be prevented as well. |
