Patent ID: 8500615

Claim:
A magnetic roller having a plurality of magnetic poles including a main magnetic pole, an adjacent magnetic pole adjacent to the main magnetic pole on a reverse-rotation direction side of the magnetic roller, and at least one other magnetic pole, wherein the main magnetic pole exhibits a magnetic force that is the highest magnetic force among all of the magnetic poles and wherein the adjacent magnetic pole exhibits a magnetic force that is higher than the magnetic force of the at least one other magnetic pole, comprising: a solid-core roller, the entirety of the roller having magnetic anisotropy in the same direction orthogonal to a central axis thereof, the solid-core roller, including: a body part; and shaft parts disposed on both ends of the body part; and a concave groove provided at a single circumferential location in an outer circumference face of the body part to extend in an axial direction; and a magnetic block disposed in the concave groove to provide the main magnetic pole, the magnetic block having a direction of magnetic anisotropy substantially orthogonal to the direction of the magnetic anisotropy of the solid-core roller, wherein the concave groove comprises the only groove in the outer circumference face of the body part having a magnetic block disposed therein.