Patent ID: 8494420

Claim:
A development agent supply device configured to supply charged development agent to an intended device, comprising: a development agent holding member that comprises a development agent holding surface that is formed to be a cylindrical circumferential surface parallel to a first direction and disposed to face the intended device in a first position, the development agent holding member being configured to rotate around an axis parallel to the first direction such that the development agent holding surface moves in a second direction perpendicular to the first direction; a transfer board provided along a development agent transfer path perpendicular to the first direction, the transfer board being configured to charge development agent on the development agent transfer path and transfer the charged development agent along the development agent transfer path to a second position where the transfer board faces the development agent holding surface in closest proximity to the development agent holding surface, such that the charged development agent is transferred to and held on the development agent holding surface in the second position; and a facing member disposed to face the development agent holding surface in a position between the first position and the second position in the second direction, the facing member being configured to charge the development agent held on the development agent holding surface under an alternating electric field generated between the facing member and the development agent holding member, the facing member is applied with a single voltage.