| 摘要 |
PURPOSE:To achieve excellent copying even at a low humidity, by providing an insulating base for perforated screen and a resistance layer provided at copying member carrying side. CONSTITUTION:A screen 322 has a base 323 knitted with a substance having a high resistance rate such as nylon as fibers or perforation. At the side contacting with a copying member of the base 323, a resistance layer 324 with a slight conductivity made of semiconductor such as zinc oxide, metallic oxide such as tin oxide, and surface active agent such as alkyl phosphate is coated. It is desirable that the volume resistance rate of the base 323 is >=10<12> ohm-m and the surface resistance rate of the resistance layer 324 is 10<10>-2X10<12> ohms. Although a paper 201 is electrostatistically adsorbed on the side of resistance layer of the screen 322, the adsorbing force comes mainly from the attracting force caused by charges with a corona charger 25 at the back side of the base 323 and those of opposite polarity introduced inside of the paper 201. |
