| 摘要 |
PURPOSE:To enhance image density by using a mixture of carrier particles coated with a fluororesin and carrier particles coated with a methyl methacrylate resin with toner particles obtained by incorporating a negative type material into a binder resin. CONSTITUTION:A binary developer is prepared by mixing the carrier particles coated with a fluororesin and carrier particles coated with a methyl methacrylate resin with the toner particles obtained by incorporating a negative type material into a binder resin. The developer is controlled to an electric charge quantity of -30--10C/g, Iron, cobalt, nickel, copper, aluminum, zinc, or brass having a particle diameter of 20-1,000mum, sand, glass powder, or the like is used for the core of the carrier, thus permitting an image high in image density to be formed by using the developer mixed with the carrier different in the coating material and stabilized in charge quantity. |
