Patent ID: 7759040

Claim:
A developer for developing an electrostatic latent image, the developer comprising: a carrier comprising a core material and a coating resin; and a toner including coloring particles which at least contain a binder resin, a coloring agent and a releasing agent, and an external additive, wherein the carrier has a median of an arithmetic average height distribution of from 0.45 to 0.65 μm, the core material has a volume average particle diameter of from 10 to 55 μm, the core material comprises magnetic particles having a saturation magnetization at 3,000 Oe of 50 A·m 2 /kg or more, the toner has an average circularity of 0.975 or more, and the circularity is defined by: ( Circularity ) = ⁢ ( peripheral ⁢ ⁢ length ⁢ ⁢ of ⁢ ⁢ equivalent ⁢ ⁢ circle ⁢ ⁢ diameter ) / ⁢ ( Peripheral ⁢ ⁢ length ) = ⁢ ( 2 × ( A ⁢ ⁢ π ) 1 / 2 ) / PM where A represents a projected area of a particle, and PM represents a peripheral length of a particle.