Patent ID: 8385783

Claim:
A development device, comprising: a development portion to develop a latent image formed on a latent image carrying member with developer including toner and carrier particles; a circulation unit to convey the developer collected from the development portion to the development portion, the circulation unit including a container to store the developer, disposed upstream from the development portion in a direction in which the developer is circulated; and a first agitator provided inside the container, to agitate and mix the collected developer and fresh toner supplied to the container, the first agitator comprising multiple linear members, wherein the multiple linear members forming the first agitator each comprise a vertical portion extending in substantially a vertical direction, with gaps between adjacent linear members in a horizontal direction perpendicular to the vertical direction; the gaps in the horizontal direction are sized to allow the carrier particles included in the developer to pass through the gaps, and the linear members have a thickness that enables the linear members to move the toner as the linear members rotate through the toner; and wherein the container includes a lower, funnel-like portion of downwardly decreasing diameter, wherein a supply port is provided in an upper portion of the container and a discharge port is provided in a lower portion thereof, and the first agitator agitates the developer supplied from the supply port in a direction to impede movement of the developer falling downward by force of gravity.