| 摘要 |
PURPOSE:To obtain constantly stable image despite the change in process speed by changing the frequency of the alternating electric field to be applied to a nonimage part according to the peripheral speeds of an electrostatic latent image holding body. CONSTITUTION:An electrostatic latent image holding body 1 having a back electrode formed of a positive electrostatic image by a multistylus electrode and a nonmagnetic developer carrying body 2 including a permanent magnet 3 are opposed by holding a clearance of more than the thickness of the developer layer in a developing part, and are rotated in the same direction at an equal speed. After the insulation-characteristic magnetic toner 5 housed in a toner vessel 7 is carried on the surface of the carrying body 2, the coating thickness is regulated uniformly with a magnetic blade 6 and the low frequency alternating electric field is applied between the image holding body 1 and the carrying body 2 by a power source 9 in such a manner that the electric fields alternate at least in the nonimage part; in addition, the frequency of the alternating electric field is changed in proportion to the peripheral speeds of the holding body 1 by a control device 11. |
