Patent ID: 8067141
Filing Date: 2011-11-29
Classification: G03G

Abstract:
1. A carrier, comprising: a core of magnetic material; and a resin layer located overlying the core, wherein the carrier has a weight average particle diameter (Dw) of from 22 to 50 μm, a ratio (Dw/Dp) of the weight average particle diameter (Dw) to a number average particle diameter (Dp) of from 1.13 to 1.30, a shape factor SF-1 of from 104 to 120, and a shape factor SF-2 of from 105 to 120, wherein the carrier comprises core particles satisfying the following relationship (1) in an amount of from 1,000 to 10,000 ppm by number: wherein D (μm) represents a diameter of a circle having the same area as that of a projected image of a core particle and d (μm) represents a diameter of a circle having the same area as that of a projected image of a maximum hollow present in the core particle, and wherein the core is prepared by a method comprising melting a core material and spheroidizing the melted core material in a gas phase.