US 7,572,388 B2
	Magnet compound material to be compression molded, a molded elongate magnetic, a magnet roller, a developing agent-carrying body, a developing apparatus and an image-forming apparatus
Satoshi Terashima, Zama (Japan); Sumio Kamoi, Tokyo (Japan); Yoshiyuki Takano, Hachiouji (Japan); Tsuyoshi Imamura, Sagamihara (Japan); Kyohta Koetsuka, Fujisawa (Japan); Noriyuki Kamiya, Yamato (Japan); and Mieko Terashima, Zama (Japan)
Assigned to Ricoh Company, Ltd., Tokyo (Japan)
Filed on Aug. 02, 2006, as Appl. No. 11/497,385.
Claims priority of application No. 2005-224558 (JP), filed on Aug. 02, 2005.
Prior Publication US 2007/0036590 A1, Feb. 15, 2007
Int. Cl. H01F 7/02 (2006.01)

U.S. Cl. 252—62.54  [252/62.55]

9 Claims

1. A magnet compound material to be compression molded, said magnet compound material comprising a rare earth based magnetic powder and thermoplastic binder resin particles, wherein a ratio of Dv to Dn is in a range of about 1.1 to about 1.3, Dv and Dn of the binder resin particles denoting the volume average particle diameter and the number average particle diameter of the binder resin particles, respectively.