Development device and image forming apparatus incorporating same

A developing device to develop with two-component developer an electrostatic latent image formed on a latent image bearer, the developing device comprising:

• a developer bearer to carry thereon developer supplied to the latent image bearer;
• first and second conveyance channels disposed adjacent to each other,
• the first conveyance channel from which developer is supplied to the developer bearer;
• the second conveyance channel through which developer transported from the first conveyance channel is circulated to the first conveyance channel;
• a first conveying member disposed in the first conveyance channel to agitate and transport developer by rotation;
• a second conveying member disposed in the second conveyance channel to agitate and transport developer by rotation in a predetermined developer conveyance direction, the second conveying member including a spiral blade winding around a shaft;
• and
• a collected-developer guide to guide a part of developer that leaves the developer bearer downward to a predetermined region in the second conveyance channel with reference to the shaft of the second conveying member, the predetermined region where movement of developer by the rotation of the second conveying member is small.