ELECTROCONDUCTIVE ROLLER, AND IMAGE FORMING APPARATUS

摘要

An electroconductive roller is provided, which is imparted with lower resistance than a prior-art electroconductive roller without addition of an expensive salt and an electron conductive agent liable to cause various problems or by adding the electron conductive agent in a smaller proportion that hardly causes the problems, and an image forming apparatus employing the electroconductive roller is also provided. The electroconductive roller (1) includes a tubular base layer (4) made of an ion-conductive elastic material, and a surface layer (6) provided on an outer peripheral surface (5) of the base layer (4). The roller resistance R1 (Ω) of the base layer and the surface resistance R2 (Ω) of an outer peripheral surface (7) of the surface layer satisfy all the following expressions (1) to (3):;log R1−log R2≧2.5  (1);log R1≦7.0  (2);log R2≦4.0  (3);The image forming apparatus incorporates the electroconductive roller as a charging roller.

主权项

1. An electroconductive roller comprising:
a tubular base layer made of an ion-conductive elastic material; and a surface layer provided on an outer peripheral surface of the base layer; wherein the base layer has a roller resistance R1 (Ω) and an outer peripheral surface of the surface layer has a surface resistance R2 (Ω), and the roller resistance R1 (Ω) and the surface resistance R2 (Ω) satisfy all the following expressions (1) to (3):
log R1−log R2≧2.5  (1)log R1≦7.0  (2)log R2≦4.0  (3)