TONER CARRIER, DEVELOPING DEVICE AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide a toner carrier, a developing device and an image forming apparatus, provided with an electrode capable of improving durability on an outer peripheral surface.SOLUTION: The image forming apparatus includes the developing device. The developing device includes a developing roller 115. The developing roller 115 includes a base material 1, electrode bars, a pair of electrodes 3a and 3b, and a protective layer 4. The base material 1 includes a conductive cored bar 5 and an insulating layer 6 formed on the outer surface of the cored bar 5. The electrode bars and the pair of electrodes 3a and 3b are made of a conductive metal, and are provided on the outer surface of the insulating layer 6. The electrode bars and the pair of electrodes 3a and 3b are formed in a way that a metal film is irradiated with a laser beam and the unnecessary portion of the metal film is removed. The electrodes 3a and 3b are formed helically on the outer surface of the base material 1 and formed so that the thickness of an edge part becomes gradually thin toward the outside in its cross section.