| 摘要 |
<p>A development device includes a developer container for containing developer, a developer bearer to carry by rotation the developer contained in the developer container to a development range facing a latent image bearer, a partition dividing the developer container into an upper compartment and a lower compartment arranged vertically, an upper developer conveyance member disposed in the upper compartment, a lower developer conveyance member disposed in the lower compartment, a communication portion through which the developer moves from the lower compartment to the upper compartment, disposed in a downstream end portion of the lower compartment in a direction in which the lower developer conveyance member transports the developer, and a toner concentration detector to detect a concentration of toner in the developer beneath the communication portion inside the lower compartment.</p> |
