| 摘要 |
PURPOSE: To effectively discharge NOx inside an electrifier to prevent the occurrence of a halt memory and to prevent the electrifier from being stained by stopping ventilation from the outside to an electrifying means at least in a partial period it the midst of electrification by the electrifying means. CONSTITUTION: A corona electrifier 2 is provided with a wire, a shield and a grid which are the electrifying means for a photoreceptor drum 1. By performing the ventilation into the primary electrifier 2 by a fan 11, the concentration of ozone product inside the primary electrifier is kept equal to or under a fixed value, and the occurrence of the stoppage memory is prevented. It is desirable to clean the outside air by making it pass through a filter F once in the case of the ventilation. Furthermore, a control circuit 12 controls the ventilation from the outside to be performed only for a fixed time after finishing the discharge of the primary electrifier 2. Thus, NOx inside the primary electrifier after finishing image formation is effectively discharged and the occurrence of the halt memory is prevented without being influenced by the outside air to the utmost. |
