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.

At an end, in a longitudinal direction, of an opening in a container containing a magnetic developer, an overlap portion is provided in which a developer bearing member, a regulating member, a sealing member, and the container are arranged so as to sequentially contact one another in a direction orthogonal to a rotation axis direction. A magnetic field generating member provided inside the developer bearing member has a first area where a value of a magnetic flux density is a predetermined value in the rotation axis direction and a second area including a local minimum portion in which the value is a minimum value, within a range from an end of the second area connected to the first area to an outer end of the overlap portion in the rotation axis direction.

A developing device includes a developer containing body having an opening and containing developer, a developer carrier that is disposed facing the opening of the developer containing body, and rotates while carrying the developer, and a seal member attached over the opening of the developer containing body to seal the gap between the developer containing body and the developer carrier. The seal member includes an upstream seal part that seals between the developer containing body, and a part of the developer carrier located upstream with respect to its rotational direction, a first side seal part that seals between the developer containing body, and one axial end side of the developer carrier, and a second side seal part that seals between the developer containing body, and the other axial end side of the developer carrier. The upstream seal part, and the first and second side seal parts are integrated together.

A developer unit according to one example embodiment includes a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads. A magnetic roll is mounted on the housing. An outer surface of a sleeve of the magnetic roll is positioned to carry the developer mix from the reservoir through a front portion of the magnetic roll that is exposed from the reservoir to permit transfer of toner from the outer surface of the sleeve to a photoconductive drum and back to the reservoir as the sleeve rotates in an operative rotational direction. An air vent is positioned along a rear portion of the magnetic roll for exiting air in the reservoir from the housing. An entire opening of the air vent is positioned vertically higher than the rotational axis of the sleeve when the developer unit is in an operative orientation.

A developing device includes a casing having an opening, the casing to contain developer, and a developer bearer including a magnetized range to cause developer to stand on end on a surface of the developer bearer and an end range outside the magnetized range in a longitudinal direction of the developer bearer. The developer bearer is disposed in the casing and partly exposed from the opening with a casing gap secured between the surface of the developer bearer and an inner face of the casing. The developer bearer generates, by rotation, sucked-in airflow to collect a floating toner from the opening into the casing, and the casing gap is smaller in the end range than the magnetized range.

A developing device includes a developer bearer, a developer regulator, a casing including an opposing face to oppose the developer bearer upstream from a developing range in a direction of rotation of the developer bearer, and first, second, and third seals. The first seal includes a first end secured to the casing and a second end to contact a latent image bearer upstream from the developing range in a direction of rotation of the latent image bearer. The second seal includes a first end secured to the opposing face of the casing, and a second end to contact the first seal upstream from the developing range. The third seal includes a first end secured to the opposing face of the casing, and a second end to contact developer on the developer bearer between the developer regulator and the developing range in the direction of rotation of the developer bearer.

A developing device, a process cartridge and an image forming apparatus which are capable of suppressing inconveniences such as stagnation of a developer at a taking-in portion of the developer and deterioration of the developer due to sliding of the developer with a developer carrying member in the case where a magnetic sealing member is used are provided.

A developing device 104 includes, with respect to an axial direction of a developer carrying member 2, a first region 2a including a developing region X and a second region 2b outside the first region 2a, adjacent to the first region 2a, and having lower developer feeding power than in the first region 2a or having substantially no feeding power, at an outer peripheral surface of the developer carrying member 2, and has a constitution in which a boundary 2d between the first region 2a and the second region 2b of the outer peripheral surface of the developer carrying member 2 at end portions of the developer carrying member 2 with respect to the axial direction of the developer carrying member 2 is positioned between a magnetic sealing member 4 and a magnetic member 5 with respect to the axial direction of the developer carrying member 2.

A developing unit includes: a developer holding member that holds developer to be supplied to an image carrier on which an electrostatic latent image is formed, the developer containing toner and carrier, and that includes at least one developer attracting magnet; a covering member that covers a part of the developer holding member; and a film that is attached to the covering member at ends and an intermediate position of the film in a circumferential direction of the developer holding member so as to be in contact with the developer held on the developer holding member.

A developing device includes a developer holder that holds a developer containing toner and carrier and being supplied to an image holder forming an electrostatic latent image; a first member that is provided on a downstream side of a developing position that is a position where the developer held by the developer holder is supplied to the image holder; and a second member that is provided between the developer holder, the image holder, and the first member, that has a surface facing the developer holder, and to which an intermediate potential as a potential between a potential applied to the developer holder and a potential applied to the first member is applied.

A developing device includes a developer holder in which a stick region as a region where a developer containing toner and carrier is stuck is set excluding an end portion, and that holds the developer to be supplied to an image holder forming an electrostatic latent image, in the stick region; a magnetic plate that is positioned at the end portion of the developer holder in a second range excluding a first range in a circumferential direction; and magnets that are combined to form a magnetization pattern in the circumferential direction corresponding to the first range.