Patent ID: 9354544
Filing Date: 2016-05-31
CPC Classification: G03G

Claim Text:
1. A developing device comprising: a developing frame having an opening that extends in a longitudinal direction thereof, the developing frame including a developer accommodation chamber configured to accommodate developer; a developing roller configured to rotate about a first axis; a supply roller that is configured to rotate about a second axis parallel to the first axis and supply the developer to the developing roller, the supply roller having a surface contacting a surface of the developing roller; a layer thickness regulation member that is configured to regulate a layer thickness of the developer carried on the developing roller; a developer supply chamber provided between the developing roller and the developer accommodation chamber in a direction perpendicular to the first axis, the developer supply chamber being connected to the developer accommodation chamber via a first port, the developer supply chamber being configured to supply the developer, which is supplied from the developer accommodation chamber, to the supply roller; a developer return chamber that is provided between the developing roller and the developer accommodation chamber in the direction perpendicular to the first axis is arranged above the developer supply chamber, is connected to the developer accommodation chamber via a second port, and is configured to return the developer, which is scraped off from the developing roller by the layer thickness regulation member, to the developer accommodation chamber via the second port; a partition wall extending from the supply roller and the developer accommodation chamber, the partitioning wall partitioning the developer supply chamber and the developer return chamber; and a first developer returning unit provided in the developer return chamber, the first developer returning unit configured to convey developer on the partition wall from the developer return chamber to the developer accommodation chamber, wherein the supply roller is provided between the developing roller and the developer accommodation chamber in the developer supply chamber, wherein the developer is allowed to circulate from the developer accommodation chamber to the developer supply chamber via the first port, from the developer supply chamber to the supply roller, from the supply roller to the developing roller, from the developing roller to the developer return chamber, and from the developer return chamber to the developer accommodation chamber via the second port, wherein the developer return chamber is provided with a second developer returning unit provided between the first developer returning unit and the developer accommodation chamber in the developer return chamber, the second developer returning unit configured to convey the developer on the partition wall from the first developer returning unit to the developer accommodation chamber, wherein the developing device further comprises: wherein the first developer conveying unit is configured to convey the developer from the developer accommodation chamber to the second developer conveying unit, wherein the second developer conveying unit is configured to convey the developer from the first developer conveying unit to the supply roller, wherein the first port connects the developer accommodation chamber to the developer supply chamber including the first developer conveying unit and the second developer conveying unit, wherein the second port connects the developer accommodation chamber to the developer return chamber including the first developer returning unit and the second developer returning unit, wherein the partition wall extends between the supply roller and the developer accommodation chamber, and wherein the first developer conveying unit and the second developer conveying unit are positioned at an opposite side of the second developer returning unit relative to the partition wall.