IMAGE-FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain satisfactory developing ability without causing any soiling of a sleeve, even with prolonged use. SOLUTION: In this image-forming method, image formation is carried out with a latent image forming process, where an electrostatic latent image is formed on an electrostatic latent image carrier and a developing process, where developing is carried out by a single-component type developer provided with transported magnetic toner. In this case, developer carrier is at least provided with electroless plating on its surface, and the magnetic toner is made to contain binding resin and magnetic material. The magnetic material is magnetic iron oxide, and the magnetic material is made to incorporate an elementα, which belongs to these of long period group in the element periodic table and is set with electro,negativity between 1.0 to 2.5, greater than that in the third period, at a rate of 0.10 to 4.00% of its weight. Furthermore, the magnetic material is provided with magnetic iron oxide particles of polynuclear shape at a ratio of more than 60% of its number, or is provided with a mixture of one or two types of magnetic iron oxide chosen from among magnetic iron oxide particles where the slope part of the hexahedron is a polyhedron plane and/or magnetic iron oxide particle, where the slope part of the octahedron is a polyhedron plane and magnetic iron oxide particles of polynuclear shape, at a ratio of more than 60% of its number.