Development unit and toner cartridge for use in an image formation apparatus

A developing unit in an image forming apparatus for attachment with a removable toner cartridge, comprising:

• a case having an outer wall with a toner introduction port defined therein and a toner cartridge support formed thereon;
• a developing sleeve disposed within the case and exposed at one side of the case opposed to the toner introduction port;
• and
• a movable case shutter having a convex portion facing the case and coupled to the case adjacent to the toner cartridge support and removably sealed over the toner introduction port and having an engaging formation that is engageable with a toner cartridge to interlock and move in unison with a shutter on the toner cartridge between open and closed positions, said case shutter being pivotable along an outer wall of the case,
• wherein when a toner cartridge is coupled to the toner cartridge support on the case, the case shutter moves between the open position in which the toner introduction port is open and the case shutter is disposed against the outer wall, and the closed position in which the toner introduction port is sealed by the case shutter.

A developing assembly for an image forming apparatus, comprising:

• a developing unit including a case having a toner introduction port defined therein and a toner cartridge support formed thereon, a developing sleeve disposed within the case and exposed at one side of the case opposed to the toner introduction port, and a movable case shutter coupled to the case adjacent the toner cartridge support and removably sealed over the toner introduction port;
• and
• a toner cartridge removably coupled to the developing unit at the toner cartridge support, including a toner box having a toner exhaust port defined therein and a box shutter with a concave portion facing the toner exhaust port and contacting the toner box, said box shutter being movable with respect to the toner cartridge for removably sealing the toner exhaust port,
• wherein the case shutter and the box shutter are movable between open and closed positions when the toner introduction port and the toner exhaust port are substantially aligned.

A toner cartridge removably coupleable to a developing unit, said developing unit including a case having an outer wall with a toner introduction port defined therein and a toner cartridge support formed thereon for supporting the toner cartridge, and a movable case shutter coupled to the case adjacent to the toner cartridge support and removably sealed over the toner introduction port, said toner cartridge comprising:

• a toner box having an outer surface with a toner exhaust port defined therein;
• and
• a box shutter with a concave portion facing the toner exhaust port and contacting the toner box, said box shutter being removably sealable over the toner exhaust port,
• wherein, when the toner cartridge is coupled to the toner cartridge support on the case of the developing unit, the case shutter is displaceable to open and close the toner introduction port as the box shutter is positioned to open and close the toner exhaust port.

A developing assembly for an image forming apparatus, comprising:

• a developing unit including a case having a toner introduction port defined therein and a toner cartridge support formed thereon, a developing sleeve disposed within the case and exposed at one side of the case opposed to the toner introduction port, and a case shutter movable along an arcuate path and being coupled to the case adjacent the toner cartridge support and removably sealed over the toner introduction port;
• and
• a toner cartridge removably coupled to the developing unit at the toner cartridge support, said toner cartridge including a toner box having a toner exhaust port defined therein and a box shutter having a concave portion facing the toner exhaust port and contacting the toner box, said box shutter being movable with respect to the toner box for removably sealing the toner exhaust port,
• wherein the box shutter is positionable between positions opening and closing said toner exhaust port as the case shutter moves along said arcuate path between corresponding positions opening and closing said toner introduction port.