| 摘要 |
<p>PURPOSE:To provide a developing device preventing the charge-up of a toner at end sections even if the contact pressure of an elastic blade to a developing sleeve is high at the end sections of the blade and capable of obtaining a developed image having no density reduction at the end sections of the image. CONSTITUTION:A conducting film 2 made of a binding resin and carbon black and/or a composition material with the carbon black is formed on the surface of a developing sleeve 1, the surface roughness of the film 2 is set to Ra=0.3-5.0mum, and the surface roughness of the film 2 is made higher by 10-30& at the end sections of the sleeve 1 than at the center section. The toner quantity carried on the sleeve 1 is increased at the end sections of the sleeve 1, thus the charge-up of the toner at the end sections can be prevented even if the contact pressure of the elastic blade 3 is high.</p> |
