| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image forming method with which a high-quality image is held extremely over a long term, waste toner is reduced to be as little as possible and a large contribution to natural preservation is realized, by restraining the variation over time of the characteristic of developer, to such an extent that it can be neglected substantially. SOLUTION: The developer for electrophotography, where a coating layer including a resin layer is provided on the surface of core material consisting of at least magnetic substance, and surface roughness Rz (nm) in a region of 500 nm×500 nm on the surface of a carrier particle, isolation rate K (number %) of an external additive particulate in toner and the primary average diameter D (nm) of the additive particulate have relation shown by the following expression (1), is used in this image forming method: (1)1.5×sin[(π/2)×(K/100)]< D/Rz [In the expression (1), (sin) is trigonometric function (sine) of the expression in brackets. The unit of the expression put in the brackets of the function is radians.]. |
