| US 7,555,252 B2 | ||
| Image forming apparatus that prevents conspicuous unevenness in image density | ||
| Tomohiro Aruga, Shiojiri (Japan); Yoichi Yamada, Shiojiri (Japan); Noboru Sakurai, Chino (Japan); and Takatomo Fukumoto, Shiojiri (Japan) | ||
| Assigned to Seiko Epson Corporation, Tokyo (Japan) | ||
| Filed on Jan. 16, 2007, as Appl. No. 11/623,669. | ||
| Claims priority of application No. 2006-008821 (JP), filed on Jan. 17, 2006; and application No. 2006-008822 (JP), filed on Jan. 17, 2006. | ||
| Prior Publication US 2007/0177908 A1, Aug. 02, 2007 | ||
| Int. Cl. G03G 15/08 (2006.01) | ||
| U.S. Cl. 399—286 | 20 Claims |
| 1. An image forming apparatus comprising:
an image bearing body
that is rotatable about a central axis thereof, and
that bears a dot-like latent image, on a surface of the image bearing body, in each of a plurality of divided regions that
are arranged in rows along a direction that intersects an axial direction of the central axis at a predetermined intersection
angle; and
a developer bearing roller
that is rotatable in order to make visible, as a developer image, the dot-like latent images borne by the image bearing body,
using a developer borne on a surface of the developer bearing roller, the developer bearing roller opposing the image bearing
body such that an axial direction of the developer bearing roller is parallel to the axial direction of the image bearing
body, and
that includes a helical groove portion on the surface of the developer bearing roller, the helical groove portion being inclined
at a predetermined inclination angle with respect to the axial direction of the developer bearing roller and being formed
having a uniform pitch in the axial direction, wherein
a value that is a tangent of the inclination angle divided by a ratio of a moving speed of the surface of the developer bearing
roller to a moving speed of the surface of the image bearing body is different from a tangent of the intersection angle.
|