| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrophotographic developer which aims to obtain an image of high picture quality with high transfer efficiency and which can achieve improvement in cleaning property without decreasing the developing property of the toner, in reliability by reducing friction between a blade and a photoreceptor, or the like in good balance, and to provide a method for forming an image by using the developer. SOLUTION: The developer is a two-component developer consisting of a toner and a carrier and characterized in that the toner consists of toner mother particles and an external additive, and the external additive comprises at least two kinds or more of inorganic oxides including cerium oxide and lubricant particles, and the shape factor SF1 defined by SF1=L<2> /A×π/4×100 of the toner mother particles is 115 to 140 in average, wherein L is the maximum length of each toner mother particle and A is the projected area of each toner mother particle. |
