Brush charger for static-charging a photosensitive member and image forming apparatus

摘要

A brush charger for static-charging a photosensitive drum by a contact method has a charging brush roller. The charging brush roller has a brush of a large number of conductive fibers, and the brush is wound around a conductive support spirally. The conductive fibers are 1.5 to 4 deniers in thickness D, are 2 mm in length L and are planted at a density not less than 150,000 filaments/inch², and the thickness D and the length L of the conductive fibers meet the condition, D>=0.71L-1.61.