| US 7,539,443 B2 | ||
| Charging roller and image forming apparatus | ||
| Shinichi Kamoshida, Nagano-ken (Japan); Atsunori Kitazawa, Nagano-ken (Japan); Tadahiro Mizutani, Nagano-ken (Japan); Katsumi Okamoto, Nagano-ken (Japan); and Ken Ikuma, Nagano-ken (Japan) | ||
| Assigned to Seiko Epson Corporation, Tokyo (Japan) | ||
| Filed on Jun. 08, 2006, as Appl. No. 11/449,473. | ||
| Claims priority of application No. P2005-168084 (JP), filed on Jun. 08, 2005; application No. P2005-168085 (JP), filed on Jun. 08, 2005; application No. P2005-168086 (JP), filed on Jun. 08, 2005; application No. P2005-168087 (JP), filed on Jun. 08, 2005; and application No. P2005-168088 (JP), filed on Jun. 08, 2005. | ||
| Prior Publication US 2006/0280518 A1, Dec. 14, 2006 | ||
| Int. Cl. G03G 15/02 (2006.01) | ||
| U.S. Cl. 399—176 | 9 Claims |
| 1. A charging roller, configured to face an image carrier at a predetermined charging gap and charge the image carrier in
a non-contact state, comprising:
a conductive shaft, provided with a pair of annular concave portions formed on an outer circumferential surface at both ends
thereof;
a conductive layer, formed on the outer circumference surface at a center portion of the conductive shaft defined between
the pair of concave portions; and
an insulating layer, formed on the outer circumferential surface at outer portions of the conductive shaft from the pair of
annular concave portions,
wherein a depth of the concave portions is larger than a thickness of the conductive layer.
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