| 摘要 |
PROBLEM TO BE SOLVED: To make performable an ozoneless injection charging with a low application voltage and a clenerless system without problem independently of contamination of developer using a simple member as a contact charging member by placing charging promotion particles at a charging part being a nip part of a image carrier and a contact charging member. SOLUTION: Charging promotion particles M1, M2 are previously held on the outer peripheral surface of a charging roller 2 as a coat, and charging promotion particles m1, m2 exist in a charging part (a). And, the charging roller 2 is rotation-driven with circumferential speed of 100% in the reverse direction to a rotation direction of a photosensitive body 1 in the charging part (a), and contacted to a surface of the photosensitive body 1 with speed difference. A prescribed charging bias is applied to the charging roller 2 from a charging bias power source S1. Thereby, a peripheral surface of the rotation photosensitive body 1 is contact-charging-processed to the prescribed polarity and potential by a direct injection charging system. In this case, charging bias is applied to the charging roller 2 so that an outer peripheral surface of the photosensitive body 1 is uniformly charging-processed to approximately -700 V. |
