| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a developing roller having optimal electric characteristics in a single-component developing system, and to provide a developing device which uses the roller, a process cartridge and image forming apparatus. <P>SOLUTION: In the developing roller has at least a double-layer structure, including a base layer constituted of an elastic body provided on a surface of an electroconductive core bar; and a surface layer provided on the base layer, a complex impedance plot obtained, when an alternating voltage is applied while changing frequencies has two peaks: a first peak width of 10<SP>7</SP>-10<SP>8</SP>Ω, and a first peak height of 10<SP>6</SP>-10<SP>8</SP>Ω; and a second peak width of 10<SP>4</SP>-10<SP>7</SP>Ω, and a second peak height of 10<SP>3</SP>-10<SP>7</SP>Ω. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
