Toner conveyance device that can execute toner loosening mode, and developing device and image forming apparatus including the same

A toner conveyance device that is demountably mounted in an image forming apparatus, the toner conveyance device comprising:

• a vertical conveyance portion that has an entry port and conveys a toner or a developer containing the toner conveyed therein through the entry port by causing the toner or the developer to fall vertically, the entry port being formed at an upper end of the vertical conveyance portion and connected to a main-body-side conveyance path in the image forming apparatus;
• a horizontal conveyance portion that is connected to a lower end of the vertical conveyance portion and conveys the toner or the developer in a horizontal direction;
• a conveyance member that includes:
• a rotary shaft that is arranged in the horizontal conveyance portion along a conveyance direction of the toner or the developer;
• and
• a conveyance protrusion that is provided to protrude on an outer circumferential surface of the rotary shaft,
• the conveyance member causing the rotary shaft to rotate so that the toner or the developer in the horizontal conveyance portion is conveyed in a direction along the rotary shaft by the conveyance protrusion;
• and
• a loosening member that is arranged in the vertical conveyance portion so as to be movable in a vertical direction,
• wherein
• the loosening member is arranged so as to be movable between a first position below a connection portion between the main-body-side conveyance path and the entry port and a second position protruding upward beyond the connection portion and is reciprocatable in the vertical direction at each of the first position and the second position,
• the loosening member is arranged at the first position under its own weight when a volume of the toner or the developer in the horizontal conveyance portion is less than a prescribed value and is arranged at the second position by being pushed up by the toner or the developer when the volume of the toner or the developer in the horizontal conveyance portion is not less than the prescribed value, and
• the toner or the developer is fed into the vertical conveyance portion so as to enable execution of a toner loosening mode in which the loosening member is caused to reciprocate at the second position.