USING METHOD FOR IMAGE FORMING DEVICE

PROBLEM TO BE SOLVED: To provide an image quality more satisfactory in the point of image density, uniformity of image density and sharp image transition by executing a development under the action of the alternating electric field between a magnetic roller and a belt base body, and setting its peak-peak voltage higher than a prescribed value. SOLUTION: An electrostatic image is formed on a moving tension belt 26 and developed by passing the belt onto a receiving member 53 near a toner development unit comprising a magnetic roller 51. The belt comprises a dielectric base body 58 having a nonconductive image holding layer 59. When the tension of the moving belt is T (N/mm), the elastic coefficient of the belt base body 58 is E (N/mm2), the thickness of the belt is d (mm), and the contact angle between the belt and the receiving member 53 is α, the expression: T×sin(α/2)×103/E×d3