CONTACT DEVELOPING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a contact developing method using a regulating means made of a plate-shaped rigid member so as to form a thin layer of a toner on the surface of a developing roll and capable of forming an image free from image fog, unevenness in image density and image defects such as vertical streaks and having satisfactory image quality. SOLUTION: A toner combined with a rigid member has 6-12μm vol. average particle diameter, the number of toner particles each having <5.04μm particle diameter is <=15.0% of the total number and the number of toner particles each having >20.16μm particle diameter is <=2.0% of the total number. The number average mol.wt. (Mn) of a fixing resin in the toner is 1×10<4> -4×10<5> and the dispersion (Mw/Mn) of mol.wt. represented by the ratio of wt. average mol.wt. (Mw) to number average mol.wt. (Mn) is >1 to <35. The vol. resistivity of the toner is 6.2×10<8> -7.0×10<10>Ω. cm.