Patent ID: 8032063

Claim:
An image forming apparatus, comprising: a photosensitive member having a surface configured to support an electrostatic latent image thereon; and a developing device having a developing roller arranged to supply developer to the photosensitive member to develop the electrostatic latent image into a developer image, wherein the developing device comprises: a casing defining an external appearance of the developing device; a first developer receiving chamber provided within the casing, the first developer receiving chamber defining a first volume capable of containing the developer therein; a second developer receiving chamber provided within the casing, the second developer receiving chamber defining a second volume capable of containing the developer therein; a partition disposed between the first developer receiving chamber and the second developer receiving chamber to define a recirculation passage beneath the developing roller and a delivery developer passage provided within the casing, the delivery developer passage defining a path through which the developer moves at least from the first developer receiving chamber to the second developer receiving chamber; and a developer delivery unit provided outside of the casing, the developer delivery unit being configured to cause a movement of the developer from the first developer receiving chamber to the second developer receiving chamber.