Patent ID: 7289746

Claim:
A charging device comprising: a charging unit that charges an image bearing member; a gas separating unit that controls a percentage of air present between the image bearing member and the charging unit; a gas electrolyzing unit that electrolyzes moisture in the air present between the image bearing member and the charging unit; and a case that surrounds the charging unit, the case including a plurality of ventilations, wherein the gas separating unit includes a nitrogen enriching unit that includes a nitrogen enriching film, which is set in any one of the ventilations; and a first pressure adjusting unit, which forms a pressure difference between an inside and an outside of the case, wherein the gas separating unit supplies nitrogen enriched air to the inside of the case and the gas electrolyzing unit includes a solid polymer electrolyte film provided in another one of the ventilations; a porous cathode that is provided on a surface facing an inner side of the case in the solid polymer electrolyte film and connected to a cathode of a power supply unit; and a porous anode that is provided on a surface facing an outer side of the case in the solid polymer electrolyte film and connected to an anode of the power supply unit.