Patent ID: 7725059

Claim:
An image developer, comprising: a developer bearer configured to be rotatable facing an electrostatic latent image bearer; a developer feeder configured to feed a developer comprising a toner to the developer bearer; a developer collector configured to collect the developer separated and left from the developer bearer after the developer is fed to the electrostatic latent image bearer; a detour route comprising a developer stirrer and transfer configured to stir and transfer the developer between the developer feeder and the developer collector; a first opening configured to connect the developer feeder with the detour route; a second opening configured to connect the detour route with the developer collector; a developer supplier configured to supply the developer to the image developer; a third opening configured to connect to the developer supplier; and a detector configured to detect a toner concentration of the developer, wherein the detector is located on a downstream side of the developer collector and on an upstream side of the second opening, wherein the toner has a volume-average particle diameter of from 3 to 8 μm and a ratio (Dv/Dn) of the volume-average particle diameter (Dv) to a number-average particle diameter (Dn) thereof of from 1.00 to 1.40.