| US 7,565,099 B2 | ||
| Developing device and image forming apparatus having a toner-particle bearing roller with a helical groove portion | ||
| Yoichi Yamada, Shiojiri (Japan); Tomohiro Aruga, Shiojiri (Japan); Noboru Sakurai, Chino (Japan); Masanao Kunugi, Nagano-ken (Japan); Katsumi Okamoto, Shiojiri (Japan); and Hiroshi Kato, Shiojiri (Japan) | ||
| Assigned to Seiko Epson Corporation, Tokyo (Japan) | ||
| Filed on Oct. 30, 2006, as Appl. No. 11/554,460. | ||
| Claims priority of application No. 2005-317374 (JP), filed on Oct. 31, 2005; application No. 2005-317376 (JP), filed on Oct. 31, 2005; application No. 2005-317377 (JP), filed on Oct. 31, 2005; application No. 2005-317378 (JP), filed on Oct. 31, 2005; and application No. 2005-379774 (JP), filed on Dec. 28, 2005. | ||
| Prior Publication US 2007/0110484 A1, May 17, 2007 | ||
| Int. Cl. G03G 15/08 (2006.01) | ||
| U.S. Cl. 399—286 | 16 Claims |
| 1. A developing device comprising:
a container that contains toner particles that are for developing a latent image borne by an image bearing body; and
a toner-particle bearing roller that has a helical groove portion on a surface thereof that is for bearing the toner particles,
the helical groove portion having an inclination with respect to an axial direction and a circumferential direction of the
toner-particle bearing roller and being formed having a uniform pitch in the axial direction, wherein:
the latent image includes dot-like latent images which are formed respectively in regions divided into lattices;
the lattices can be formed having a plurality of types of pitches in the axial direction; and
a pitch of the groove portion in the axial direction is shorter than a longest pitch among a plurality of the types of the
pitches of the lattices.
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