公开(公告)号：EP1723473A4

公开(公告)日：2008-04-02

申请号：EP05720549

申请日：2005-03-04

申请人： RICOH KK

发明人： MIZUISHI HARUJI ,  OJIMI TOKUYA ,  KOIKE TOSHIO ,  SHINTANI TAKESHI ,  ARAI YUJI ,  YONEDA TAKUZI ,  AMEMIYA KEN ,  TAWADA TAKAAKI ,  TOMITA MASAMI ,  KAWASUMI MASANORI ,  MURAISHI TAKAYA ,  HARADA HIROOMI ,  NINOMIYA HIROMICHI

IPC分类号： G03G9/08 ,  G03G15/02 ,  F16C13/00 ,  G03G9/087 ,  G03G21/10 ,  G03G21/18

CPC分类号： G03G15/0225

摘要： The present invention provides a charging device which comprises a charging roller (14a) and a cleaning component (14b). The charging roller charges a surface of an image-recording medium (11) with a voltage which is applied from an external source. The cleaning component cleans a surface of the charging roller. The charging roller includes a resistance adjustment layer which is made of a resin composite and formed on an outer periphery of a core metal. The hardness of the charging roller is 45 degrees or more in JIS D hardness. The cleaning component has a portion which is in contact with the charging roller. This portion is made of resin foam which has a continuous foam structure. The density of the resin foam is 5 to 15 kg/m3 and its tensile strength is 1.7±0.5 kg/cm2.