According to an aspect of the invention, a developing device includes a developer holding member that holds developer including toner which is charged to have a predetermined polarity on a surface and performs development of an electrostatic latent image with respect to an image holding member which holds the electrostatic latent image while being rotated; a storage member that stores the developer therein and has an opening portion for discharging air in which flow is generated by the rotation of the developer holding member; and a collection member that is provided in the opening portion of the storage member to be charged to the predetermined polarity, causes air to pass therethrough, and collects toner.

According to an aspect of the invention, a developing device includes a developing container that accommodates a two-component developer, a toner concentration detecting unit that detects a toner concentration of the developer by a detecting unit exposed to an inner wall of the developing container, a transport member that is disposed within the developing container and stirs and transport the developer with a transport blade having a pitch that is equal to or less than a size of the detecting unit of the toner concentration detecting unit, and a plurality of gap holding members that is provided at a position facing the toner concentration detecting unit of the transport member and holds a gap such that a tip thereof is abutted against the inner wall of the developing container.

An image forming apparatus includes a development device, a toner storage part, a drive unit, a control unit, and an image carrying member. The development device includes a development casing, a developer carrying member, a first stirring transport member, a second stirring transport member, a discharge impeller, and a reverse transport impeller. The development casing includes a first partition wall, a communication part, a developer replenishment port, and a developer discharge part. The first stirring transport member includes a first rotation shaft and a first transport impeller. The second stirring transport member includes a second rotation shaft and a second transport impeller. The control unit can perform a developer discharge mode, in which the first rotation shaft and the second rotation shaft are rotated reversely during a non image formation period, so that the developer around the reverse transport impeller is discharged through the developer discharge part.

A unit includes a part that is detachably attachable relative to an other unit, wherein the other unit includes an opening through which image forming powder is supplied from or received by the other unit, and a shutter that opens and closes the opening, and a collecting member that collects the image forming powder falling from at least one of the opening and the shutter by making contact with the shutter when detaching the unit from the other unit.

A waste toner collecting device includes an intermediate collection box, a conveying path, a conveying screw, an exhaust path and a floating toner collection chamber. The conveying path is provided in the intermediate collection box. The conveying screw is rotatable in the conveying path. Through the exhaust path, air containing a floating toner is sucked and passed. The floating toner collection chamber is provided on a part of the exhaust path in the intermediate collection box. The floating toner collection chamber has a discharge opening opened to an inside of the intermediate collection box and a discharge door. Rotation of the conveying screw in a normal direction turns the discharge door into a storage position where the discharge opening is closed. Rotation of the conveying screw in a reverse direction turns the discharge door into a discharge position where the discharge opening is opened.

A waste toner collecting device includes an intermediate collection box, a conveying path, a conveying screw, an exhaust path and a floating toner collection chamber. The conveying path is provided in the intermediate collection box. The conveying screw is rotatable in the conveying path. Through the exhaust path, air containing a floating toner is sucked and passed. The floating toner collection chamber is provided on a part of the exhaust path in the intermediate collection box. The floating toner collection chamber has a discharge opening opened to an inside of the intermediate collection box and a discharge door. Rotation of the conveying screw in a normal direction turns the discharge door into a storage position where the discharge opening is closed. Rotation of the conveying screw in a reverse direction turns the discharge door into a discharge position where the discharge opening is opened.

A cleaning unit includes a cleaning member that removes a developer from a surface of an image holding member; an accommodating portion that accommodates the removed developer; and a transport member that transports the developer removed by the cleaning member to the accommodating portion, wherein the transport member includes a transport unit that extends in a direction intersecting with a developer transport direction, has a surface formed to be inclined in a direction approaching the cleaning member towards an upstream side, and transports the developer while contacting with the developer.

An example binary ink developer (BID) assembly includes a housing, a developer roller, a squeegee roller, and a guard member. The developer roller receives ink and transfers a portion of the ink to a photoconductive member. The squeegee roller rotates and regulates a film thickness of ink on the developer roller. The squeegee roller includes a curved circumference. The guard member includes a conforming end disposed across from the squeegee roller. Further, the conforming end has a concave shape corresponding to a portion of the curved circumference of the squeegee roller.

A developing device includes a developer container, a developer carrier, and first and second members for stirring/conveying. The developer container includes a first partition wall between first and second chambers, a communication portion through which those chambers communicate at opposite ends of the first partition wall, a developer supply port, and a developer discharge portion. The first member stirs and conveys developer in the first chamber in a first direction. The second member stirs and conveys developer in the second chamber in a second direction and includes a regulating portion and a discharging blade. The developer container includes a second partition wall between the first chamber and the regulating portion. The gap from the upper end of the second partition wall to the inner surface of the developer container is larger than the gap thereto from the upper ends of a first helical blade and the regulating portion.

A cartridge attachable to and detachable from an image forming apparatus forming an image on a recording material, the cartridge includes: an image bearing member; a developer container that contains therein a developer; a developing member that is rotatable and carries the developer supplied from the developer container and supplies the developer to the image bearing member; a developer supplying member that is rotatable and provided in the developer container and in contact with the developing member to supply the developer to a surface of the developing member; and a contact member provided in the developer container and in contact with a surface of the developer supplying member, wherein the developer remaining on the image bearing member after image formation is collected to the developing member, and the developer collected to the developing member is collected into the developer container.