| 摘要 |
PURPOSE:To optimize development, charging and layer thinning processes by using a hollow body as a developing carrier and individually controlling bias voltage. CONSTITUTION:Supporting rollers 18 to 20 for rotationally supporting a cylindrical developing roller 15 formed by a dielectric hollow body are arranged on the inner peripheral side of the roller 15. At the time of executing development by successively executing a charging process, a layer thinning process and a developing process, bias voltage is impressed from a bias power supply 22 to the roller 19 arranged on a position opposed to a feeding roller 16 through the roller 15 to adjust primary toner feeding amount to the roller 15 and control the charging quantity of toner. Namely the surface potential of the roller 15 on the part corresponding to the roller 16 is independently coratrolled by the bias voltage independently set up by the power supply 22. Then bias voltage is impressed from a bias power supply 23 to the roller 20 to control/adjust the thickness of a toner thin layer and charging quantity on the surface of the roller 15. |
