| 摘要 |
PURPOSE:To obtain a high quality image by obtaining a high image density, and further, excellent reproducibility and gradation in a diagram, and preventing the occurrence of a moire pattern on an image. CONSTITUTION:A developing roller 20 having the formation of a surface layer made of a conductive material on which an insulating grain is dispersed, on a conductive substrate, and the mixture of a conductor part made of the conductive material and an insulator part on which an insulating grain is exposed, on a surface, is disposed to be opposite to the surface of a photosensitive drum 10 on which an electrostatic latent image is formed, in the gap of 100mum. The insulator part is rubbed by a toner supplying roller 40, holds the charge of a positive polarity, and carries negatively electrified toner 7. A pulse voltage is impressed on the developing roller 20 to execute reversal development. |
