Patent ID: 7792465

Claim:
A developing device for accommodating a developer including carriers and a toner, and for developing a latent image formed on an image carrier, the developing device comprising: a plurality of developer conveying units configured to convey the developer accommodated in the developing device, and form circulating paths; a plurality of developer apertures configured to allow conveyance of developer between two or more of the plurality of developer conveying units, the plurality of developer apertures disposed proximate to one or more ends of the developing device in a lengthwise direction; and a ventilation unit configured to perform ventilation between at least one of the developer conveying units whose internal pressure increases and at least one of the developer conveying units whose internal pressure decreases, wherein the ventilation unit includes a plurality of ventilation aperture paths through one or more barrier members between the plurality of developer conveying units, the ventilation aperture paths disposed remote from the plurality of developer apertures.