Development device and image forming device that prevents toner leakage
A development device includes a development tank that stores a developer, a first screw and a second screw that convey the developer, an exhaust port through which air inside the development tank is exhausted, and a filter provided at the exhaust port. The development tank includes a first holder provided with a first screw, a second holder provided with a second screw, a partition wall that partitions the first holder and the second holder, and a first flow port and a second flow port that open the partition wall and through which the developer flows between the first holder and the second holder. A shield partitions the first holder and the exhaust port, and the second holder is connected to the exhaust port.
1 . A development device comprising:
a development tank that stores a developer, the developer including a toner;
a developer carrier that carries the developer;
a first conveyance member and a second conveyance member that have rotary shafts being in parallel with each other and facing each other, that stir and convey the developer in the development tank, and that supply the developer to the developer carrier;
an exhaust port through which air inside the development tank is exhausted; and
a filter that is provided at the exhaust port and that collects the developer included in the exhausted air, wherein:
the development tank is provided with:
a first holder provided with the first conveyance member and disposed at a near side to the developer carrier,
a second holder provided with the second conveyance member and disposed at a far side from the developer carrier,
a partition wall that partitions the first holder and the second holder, and
a first flow port and a second flow port that are provided, respectively, at both end portions in an axial direction along the rotary shafts of the first conveyance member and the second conveyance member, and that open the partition wall, the developer flowing from the second holder to the first holder through the first flow port, the developer flowing from the first holder to the second holder through the second flow port,
a shield partitions the first holder and the exhaust port,
the second holder is connected to the exhaust port, and is provided with an exhaust path above the second conveyance member, the exhaust path extending upward along the partition wall,
the exhaust path is a gap having a width smaller than a width of the second conveyance member, and has a common space located, at a position higher than the shield, above both the first holder and the second holder,
the exhaust port is located across and above the first holder and the second holder via the common space, and
the filter is disposed in an inclined manner as a side of the second holder is higher than a side of the first holder.
2 . The development device according to claim 1 , wherein
the second flow port has an opening area larger than an opening area of the first flow port.
3 . The development device according to claim 1 , wherein
the developer carrier is provided above the first conveyance member, and
the partition wall is provided with a ventilation port that opens at a portion facing the developer carrier in a horizontal direction.
4 . The development device according to claim 1 , wherein
the developer carrier is provided above the first conveyance member, and
the shield is provided above the developer carrier.
5 . The development device according to claim 1 , wherein
the exhaust port is provided at an upper portion of the development tank and extends in the axial direction.
6 . An image forming device comprising:
the development device according to claim 1 , wherein
the exhaust port is connected to a duct through which air passes via the filter, and
the duct is provided with an intake fan that suctions air from the development tank.
7 . The image forming device according to claim 6 , wherein
the intake fan suctions air from the development tank after image formation.
8 . The image forming device according to claim 6 , further comprising:
a printing rate determinator that determines a printing rate which is a rate of an image printed on a sheet; and
a sheet number counter that counts a number of sheets on each of which the image is formed, wherein
the intake fan suctions air from the development tank at a time that a toner consumption amount exceeds a reference value based on the printing rate and the number of sheets in image formation.