| 摘要 |
PURPOSE:To obtain a distinct two-color toner picture for many hours by electrifying by an AC corona discharge in case of electrification, exposure and development of the second time after executing each process of electrification, exposure and development of the first time. CONSTITUTION:An operation of a capacitor 19 cuts a DC component and passes an AC component through so that absolute values of positive and negative currents become equal because an AC discharge itself generates a lot of negative currents. In case of DC electrification, the potential of the whole area of the surface potential of a photosensitive body increases (7-2). In case of AC electrification, a negative polarity corona discharge is received in a potential area of >=+500V before receiving the electrification, and a positive polarity corona discharge is received in a potential area of <=+500V (7-1). In this way, the polarity of both a black toner and a red toner formed on the surface of a photosensitive body 1 is a negative polarity, therefore, it is unnecessary to execute polarity matching before transfer, and a distinct two-color toner picture is obtained. |
