Patent ID: 8000631

Claim:
A developing device for visualizing an electrostatic latent image comprising: a toner carrier for a nonmagnetic monocomponent toner having a charge quantity per unit mass of q/m (C/kg); means for applying to the toner carrier an AC bias having a frequency f (Hz) and an amplitude Vpp (V), and an amorphous silicon photoconductor on which the electrostatic latent image has been formed, wherein the frequency f of the AC bias applied to the toner carrier is adjusted to a value within a range of from 2×10 3 to 10×10 3 Hz, the amplitude Vpp(V) is adjusted to a value within the range of from 500 to 1500 V, the charge quantity q/m (C/kg) per unit mass of the nonmagnetic monocomponent toner is adjusted to a value within the range of from 0.5×10 −2 to 3×10 −2 C/kg, the amorphous silicon photoconductor is disposed so that a distance Ds (m) between the amorphous silicon photoconductor and the toner carrier is adjusted to a value within a range of from 0.5×10 −4 to 1×10 −4 m, a ratio θ (−) of a peripheral speed of the toner carrier to a peripheral speed of the amorphous silicon photoconductor is adjusted to a value within the range of from 0.5 to 2, and wherein the frequency f, the ratio θ, the charge quantity q/m, the amplitude Vpp and the distance Ds are adjusted so that the following relational expression (1) is satisfied: ( f× 1.5/θ) 2 >−1.576×10 −2 ×q/m ×( Vpp/Ds 2 )+31.9×10 6 (1).