TWO-COMPONENT DEVELOPER

PURPOSE:To prevent the generation of the black stripes arising from talc and the appearance of a density difference by adding a slight amt. of a material to be electrostatically charged by friction to the polarity reverse from the electrostatic chargeableness of a toner into a developer consisting of the toner and developer. CONSTITUTION:The toner 2 is electrostatically charged positive by friction with the developer not shown. The toner 2 sticks to an image part A at 300V potential difference because of the potential distribution shown in the figure. Since a non-image part B has the potential large than bias voltage -200V, the toner 2 does not stick thereto. The developer contains the material 3 to be frictionally and electrostatically charged to the polarity reverse from the charge polarity of the toner in addition to the above-mentioned toner 2 and the developer. The material 3 frictionally charged to the reverse polarity sticks in the direction reverse from the toner, i.e., to the non-image part B by having 150V potential difference. The talc sticks onto the material 3 even if the talc sticks to the non-image part by such effect of the developer; therefore, the talc is easily removed by a cleaning blade in a stage for removing the remaining toner.