| 摘要 |
PURPOSE:To improve half-tone reproducibility by applying a periodic voltage to a counter electrode and correcting the amount of magnetic toner which sticks onto a recording medium. CONSTITUTION:When the periodic voltage is applied to the counter electrode 5, the force of an electric field which is intenser than the Coulomb force operating between an electromagnetic latent image on a recording medium 4 and the magnetic toner operates on the magnetic toner, which leaves the recording medium 4 to be recovered to the counter electrode 5. When a low voltage is applied, on the other hand, the electric field force by the electrostatic latent image operates on the magnetic toner more strongly and the magnetic toner recovered to the counter electrode 5 moves to the recording medium 4. The magnetic toner is put in said alternate motions and passes through a correction area gradually at the same time. Namely, the applied voltage becomes lower according to the distance from the closest point between the counter electrode 5 and recording medium 4 to stick the toner to the electrostatic latent image on the recording medium with good balance. Thus, the half-tone reproducibility is improved. |
