Preset case, development apparatus, process cartridge, and image forming apparatus

A preset case for keeping therein unused initial fill of developer, the preset case being disposed on top of a developing apparatus, the developing apparatus comprising:

• a developer container including a developer transportation unit that transports, while mixing, a developer containing a toner and a carrier along an axis of rotation by a rotatable mixing transportation member, and a toner concentration detection unit that detects a concentration of the toner to be transported inside the developer transportation unit;
• and
• a hold-down wall that holds down the toner in a gravitationally downward direction by coming into contact with the toner from a gravitationally upper side, the toner moving upward from a gravitationally lower side as a result of rotation of the mixing transportation member, the hold-down wall being disposed in a region, out of an entire region in the direction of developer transportation at the developer transportation unit, in which a bottom wall of the developer transportation unit lies opposite to the gravitationally lower side of the mixing transportation member and in which side walls of the developer transportation unit lie opposite to each other on both sides that cross at right angles to an axis of rotation of the mixing transportation member,
• the preset case comprising:
• a developer feed port provided on that bottom surface of the preset case which lies on a side of the developer container;
• a sealing member that seals the developer feed port, the sealing member being mounted so as to be removable, when putting the preset case to use, in a longitudinal direction of the mixing transportation member,
• wherein the developer feed port is provided except for a position that lies opposite to the cover member disposed in the developer transportation unit.

A development apparatus comprising:

• a developer container having a developer transportation unit that transports, while mixing, a developer containing a toner and a carrier along an axis of rotation by a rotatable mixing transportation member;
• a cover member provided, out of an entire region as seen in a direction of transportation of the developer, in part of the developer transportation unit so as to cover an upper portion of the mixing transportation member;
• and
• a preset case that keeps therein unused initial fill of developer, the preset case being disposed on top of the developer transportation unit, the preset case comprising:
• a developer feed port provided at a bottom surface thereof on a side of the developer container;
• a sealing member for sealing the developer feed port, the sealing member being mounted so as to be removable, when putting the preset case to use, in a longitudinal direction of the mixing transportation member, the developer feed port being provided except for a position that lies opposite to the cover member disposed in the developer transportation unit.