| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a developing roller which carries an optimum amount of toner and prevents an electrostatic charge defect. <P>SOLUTION: In the developing roller, a plurality of first grooves formed at approximately equal intervals in a direction oblique to a circumferential direction and a plurality of second grooves formed in parallel to each other and at approximately equal intervals in a direction oblique to the circumferential direction, and intersecting with each first groove, are formed. Cross sections of the first grooves and the second grooves are formed in U shapes respectively and projecting parts whose top surfaces surrounded by the first grooves and the second grooves are approximately planes. When the width of the first first grooves is defined as A1, the width of the second grooves as B1, the length of the top surfaces parallel to the second grooves of the projecting parts as C1, and the length of the top surfaces parallel to the first grooves of the projecting parts as C2, relationships of A1>C1 and B1>C2 are satisfied and when the maximum depth of the first grooves is defined as D1, and the maximum depth of the second grooves as D2, D1 and D2 are 0.5 to 2 times the average grain size of the toner particles, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
