| 摘要 |
PURPOSE:To form a picture of a high quality even when a low voltage is impressed to the electrode of a carrying body by constituting so that an electric resistance flies in a good state a developer of a prescribed range by an electric field which is generated between plural electrodes of a developer carrying body and varied with lapse of time. CONSTITUTION:When a cylindical roller 4 is rotated, a developer 31 rubbed by the roller 4 and an elastic blade 12 is electrostatically charged to the negative polarity. On the other hand, electrodes 51-55, etc. of the roller 4 opposed to an electrostatic image holding body 1 are driven by AC and DC voltages alternately, and an electric field which is varied with lapse of time is generated among the electrodes 51-55, etc. In accordance with this electric field, the developer executes a reciprocating movement, flies in a good state a smoke state for forming a picture of a high quality. Accordingly, a developer having a low resistance of 10<3>-10<8>OMEGAcm is used to form a picture of a high quality when a low voltage is impressed to the electrode of the developer carrying body. |
