CONTACT CHARGING DEVICE

PROBLEM TO BE SOLVED: To obtain stable charging characteristics even to change of temperature and humidity and to avoid generation of a filming phenomenon even when lubricant is provided to a photosensitive body. SOLUTION: In this contact charging device which applies voltage of AC + DC to a charging roller 2, when AC current by which surface potential of the photosensitive body 3 is stabilized to a predetermined value and becomes constant when the AC current is changed by applying the voltage of AC + DC to the charging roller 2 is a surface potential stabilizing current value Ih, a current value equal to or more than the surface potential stabilizing current value Ih to 1.5 times the surface potential stabilizing current value Ih is the AC current to be applied to the charging roller 2. By doing in this way, change of surface charging potential of a charged body in accordance with environmental change such as temperature and humidity is small in comparison with that in the case of applying only DC voltage. In addition, since the AC current to be applied to the charging roller 2 is regulated in the above-mentioned range, occurrence of ozone is reduced. COPYRIGHT: (C)2005,JPO&NCIPI