Sharp Kabushiki Kaisha Corporation

Hiroshi Tanisawa

Hiroshi Kawahito

Yasuyuki Ishiguro

Hisashi Kunihiro

Takeshi Wakabayashi

Fumito Mizoguchi

Jun Yamaguchi

Hiroshi Kubota

Toshio Nishino

Tsutomu Nagata

Yoshinori Otsuka

Masatoshi Kaneshige

Naotaka Funayama

Haruko Yoneda

Hideaki Hagihara

Yoshiaki Sanada

Hiroshige Araki

Akira Nakakuma

A developing device includes: a first conveying passage (developer conveying passage) through which a developer containing a toner and a magnetic carrier is conveyed; a first conveying member (developer conveying member) provided in the first conveying passage for agitating and conveying the developer in a predetermined direction; and a toner supply pipe for leading supplementary toner to the first conveying passage. The developing device further includes electromagnets for forming a magnetic field inside the toner supply pipe to create a magnetic brush shutter by means of the electromagnets.

Image forming apparatus including a developing device with toner supply passage having a magnetic field formed inside and toner supply control method using the same

A communication unit has a first conveyance part connected to a toner cartridge and provided with a feed port for a toner from the toner cartridge, and a second conveyance part connected to a developing device and provided with a replenishment port for a toner to the developing device. In a state locked by the lock mechanism, the first conveyance part and the second conveyance part are connected to each other, and the feed port of the first conveyance part and the replenishment port of the second conveyance part are opened, allowing for a toner replenishment. In a lock-released state, the feed port of the first conveyance part and the replenishment port of the second conveyance part are closed by a circular arc-shaped shutter member and a rotary shutter member, allowing the first conveyance part and the second conveyance part to be separable from each other.

Image forming apparatus

A toner container has a partitioning wall disposed therein for partitioning the toner container while allowing communication between partitioned compartments. A waste toner collecting port for receiving the waste toner collected by the cleaning unit of an image forming apparatus is formed in a waste toner collection department. A toner agitating element for mixing waste toner with unused toner is located inside the partitioned waste toner collection compartment.

Toner cartridge for image forming apparatus

Sensitive drum cartridge for an image forming apparatus

Toner cartridge

Developing unit for an image forming apparatus

The length of a conveying sheet is set to be greater than the rotational radius of an agitating element so that the distal end of the conveying sheet will slide over the inner wall of the toner container. A slider element having a low frictional resistance is attached at the distal end of the conveying sheet. The slider element preferably has a low coefficient of dynamic friction and is preferably made of a soft resilient material having a thickness smaller than the conveying sheet. Cutouts or openings may be preferably formed at the distal part. A multiple number of ribs are attached to the wall surface of the toner container at the highest position at which the wall and the top plate meet. The ribs are arranged apart from each other in the direction parallel to the agitating shaft of the agitating element. Each rib is a plate-like element projected inward from the wall surface in the toner container with its width put in the direction of the spacing. Further the end portions of the ribs on the interior side of the toner container are adapted to form a curved surface smoothly connecting the top plate surface and the wall surface.

Toner supply device with rotatable agitating element

A developing unit includes a developing hopper, a toner reserve container that incorporates a replenishing roller and a replenishing port forming a toner replenishing portion, arranged adjacent to the developing hopper in order to supply the toner to the developing hopper. The toner reserve container further includes an agitator rotatable about a rotary shaft and a conveying sheet attached to the agitator for conveying the toner to the replenishing roller. The conveying sheet has a bent portion where the conveying sheet is bent in the rotational direction of the agitator at a halfway point thereof with a predetermined angle &agr;. Deformation of the conveying sheet during rotation is absorbed around the position of the bent portion, so that the conveying sheet will not be plastically deformed at the attached part of the conveying sheet joined to the attachment edge of the agitator, whereby long stable toner conveyance by the conveying sheet can be maintained.

Developing unit equipped with a toner replenishing device configured with a conveying sheet and rotator

A developing unit includes a developer hopper, a toner reserve container that incorporates a replenishing roller and a replenishing opening forming a toner replenishing portion, arranged adjacent to the developer hopper in order to replenish the toner to the developer hopper. The toner reserve container further includes an agitator rotatable about a rotary shaft with a conveying sheet for conveying the toner to the replenishing roller. The conveying sheet is attached to the agitator so that it becomes close to the rotary shaft of the agitator. By this configuration, an adequate space can be secured between the top plate, i.e., an operable/closable lid, constituting the toner reserve container and the conveying sheet so that the distal part of the conveying sheet can efficiently retain the toner, thus making it possible to improve the conveyance performance to the replenishing roller and realize an uniform amount of conveyance.

Developing unit and toner replenishing device with conveying apparatus

A developer cartridge capable of being fitted to the toner replenishing opening of a developer storage hopper has a sealing member for sealing the toner therein that is bonded to the rim of its replenishing opening to be opposed to the opening of the developer storage hopper. The bottom face of this developer cartridge which constitutes the bottom for supporting the toner stored therein is inclined upwards in the stripping direction of the sealing member, whereby the supplied amount of the toner at the stripping start of the sealing member is regulated when the sealing member is stripped so that the toner can be uniformly supplied across the full length of the developer storage hopper with respect to the stripping direction of the sealing member.

Developer cartridge

Growing community of inventors

Nara, Japan

Hiroshi Tanisawa