US Patent 7697874 Developer supply roller and image forming apparatus

To provide a developer supply roller including: a shaft core; and an elastic layer over the shaft core, wherein the elastic layer is composed of at least a first elastic layer and a second elastic layer, the first elastic layer and second elastic layer made of elastic bodies with different moduli of elasticity, the first layer being an outermost layer of the supply roller, and wherein the relationships 0%≦k1≦20% and 20%≦k2≦70% are satisfied, where k1 is the modulus of repulsion elasticity of the first elastic layer and k2 is the modulus of repulsion elasticity (%) of the second elastic layer.