Patent ID: 8326203

Claim:
A toner conveyance device comprising: a toner conveyance path configured to convey toner from a lower position to an upper position; a lower holding member provided at the lower position in the toner conveyance path and defining a belt delivery part; an upper holding member provided at the upper position in the toner conveyance path; a conveyance belt extended around the upper holding member and the lower holding member provided in the toner conveyance path and driven to circulate by the upper holding member working in conjunction with the lower holding member, the conveyance belt running obliquely upward at a lower-side region, running obliquely downward at an upper-side region, and including a projection to hold and convey the toner with a wall of the toner conveyance path and engagement grooves communicating an inner side of the conveyance belt with an outer side of the conveyance belt, formed at predetermined intervals in a running direction of the conveyance belt so as to transfer a drive force to the conveyance belt; and a guide member provided in a space inside a circulating loop formed by the conveyance belt to prevent the conveyance belt from collapsing, a lowest portion of the guide member at the upper-side region being placed on a substantially vertical line drawn from the belt delivery part of the lower holding member at the lower-side region.