Developing method using single-component nonmagnetic toners

A contact-type developing method for developing a static latent image using a single-component non-magnetic toner, comprising the steps of:

• a) preparing (1) a developing device having at least a developing roll for carrying a toner and a control member for controlling the thickness of a toner layer provided near the developing roll and, (2) a single-component non-magnetic toner consisting essentially of a coloring agent and a binder resin of a styrene copolymer having a number average molecular weight of 8,000 to 30,000 and a weight average molecular weight of 100,000 to 300,000, and having a single peak molecular-weight distribution in a gel partition chromatograph, wherein the styrene copolymer is obtained by a polymerization reaction between (i) a styrene monomer selected from the group consisting of styrene, .alpha.-methyl-styrene, p-chlorostyrene, and their derivatives and (ii) a compounds selected from the group consisting of an acrylic alkyl ester wherein the alkyl group has 1 to 15 carbon atoms, a methacrylic alkyl ester wherein the alkyl group has 2 to 15 carbon atoms, and a vinyl monomer;
• b) feeding the single-component non-magnetic toner into the developing roll;
• c) forming a thin layer of toner by virtue of the control member for controlling the thickness of the toner layer to charge the toner;
• d) causing the charged toner to contact with a carrier for holding a static latent image to develop the static latent image;
• and
• e) transferring the latent image to paper.