Patent ID: 8023863

Claim:
A charging apparatus comprising: a discharging electrode for applying a voltage to a surface of a photoreceptor so as to electrically charge the surface of the photoreceptor; and a grid electrode disposed between the discharging electrode and the photoreceptor, for controlling a charged potential on the surface of the photoreceptor, the grid electrode having a protective layer made of nickel and phosphorus for surface protection formed at least on its one surface, the protective layer fulfilling a following formula (1) and a condition of 8≦x 1 ≦15, (−0.7 x 1 +11)≦ y 1 ≦(−0.7 x 1 +27) (1), where a concentration of phosphorus in the protective layer is defined as x 1 (%) and a proportion of a one-surface thickness of the protective layer Z 2 to a thickness of the grid electrode Z 1 given as (Z 2 /Z 1 )×100 is defined as y 1 (%).