Abstract: A charging roller is constituted of a shaft, a conductive elastic cylinder, and a charging layer. The shaft is integrally covered with the conductive elastic cylinder. Further, the conductive elastic cylinder is integrally covered with the charging layer. The charging roller formed in this way is restored such that it is loosely encased in a seamless charging tube having semi-conductivity.

Abstract: A charging device or a transfer device used for an electrophotographic printer includes a charging unit. In this charging unit, a shaft is loosely encased by a conductive elastic cylinder. Further, the conductive elastic cylinder is loosely encased by a seamless charging tube. As to the charging device, the charging unit is pressed against a photosensitive drum. The seamless charging tube and the conductive elastic cylinder are driven to rotate in association with a rotation of the photo sensitive drum. A charging voltage is applied between the seamless charging tube and the photosensitive drum.