| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce adhesion of foreign substances to a surface of a charging roller for a long period of time from an initial period of use of the charging roller until expiration of service life thereof, and to suppress an image defect due to the adhesion of the foreign substances to the surface of the charging roller. <P>SOLUTION: A charging roller has a nano structure layer provided with a plurality of protrusions having columnar structures on a surface as a surface layer. A mean value of diameters of the plurality of protrusions is 5 nm or more and 200 nm or less, and a mean value of distances among the protrusions adjacent to one another is 20 nm or more and 700 nm or less. The protrusions are formed of a block copolymer of two polymers having carbon density of monomer units different from each other. <P>COPYRIGHT: (C)2013,JPO&INPIT |
