| 摘要 |
PROBLEM TO BE SOLVED: To enable satisfactory transfer by specifying the time constant of a transfer drum, thereby making an electric field by the transfer drum stable. SOLUTION: The device is equipped with a photoreceptive drum 15 on the surface of which a toner image is formed, the transfer drum 11 which transfers the toner image to a transfer material by bringing the transfer material into contact with the photoreceptive drum 15, and a ground roller 12 which electrostatically attracts the transfer material to the transfer drum 11 before the transfer of the toner image to the transfer material. The transfer drum 11 is constituted by bonding a semiconductive layer and a dielectric layer onto a conductive layer. The device satisfies the relationship of L1/Vp<τ, wherein L1 is the width of a nip between the photoreceptive drum 15 and the transfer drum 11, Vp is the speed of the rotation of each of the two drums, and τ is the time constant of the transfer drum 11 expressed by the product of resistance and electrostatic capacity between the two drums. |
