Developer container and method for filling the same

1. A developer container comprising: a container chamber that has a container space for containing a developer; and

a conveyance member having a rotation shaft and a spiral member which rotates inside the container space about the rotation shaft as a rotation center, the spiral member including a plurality of high-angle portions and a plurality of low-angle portions, the spiral member being spirally extended to an axial direction of the rotation shaft, angles of spirally extending directions of each of the plurality of high-angle portions to the axial direction being a first angle, angles of spirally extending directions of the plurality of low-angle portions to the axial direction being a second angle, which is smaller than the first angle, wherein

at least one of the low-angle portions is provided in each unit segment which is equivalent to one turn of the spiral member about the rotation shaft, and

an amount of a developer contained in the container space is enough to constantly bury one of the plurality of low-angle portions in the developer under a condition that the axial direction of the rotation shaft is held to be horizontal inside the container space,

wherein the conveyance member further has a plurality of first connection parts, each of which connects the rotation shaft to the spiral member, and each one of the plurality of first connection parts is provided between adjacent two of the plurality of low-angle portions, with an exception that a first connection part is provided at each end of the rotation shaft,

wherein, when viewed in a direction parallel to the axial direction of the rotation shaft, an angle of approximately 90 degrees is held between directions of the first connection parts extended to the spiral member and perpendicular lines extended from centers of the plurality of low-angle portions to the rotation shaft.

2. The developer container according to claim 1 , wherein the amount of the developer contained in the container space is not enough to bury whole of the conveyance member in the developer.

3. A developer container comprising:

a container chamber that has a container space for containing a developer;

a conveyance member having a rotation shaft and a spiral member which rotates inside the container space about the rotation shaft as a rotation center, the spiral member including a plurality of high-angle portions and a plurality of low-angle portions, the spiral member being spirally extended to an axial direction of the rotation shaft, angles of spirally extending directions of each of the plurality of high-angle portions to the axial direction being a first angle, angles of spirally extending directions of the plurality of low-angle portions to the axial direction being a second angle, which is smaller than the first angle; and

a plurality of second connection parts respectively connecting the plurality of low-angle portions to the rotation shaft,

wherein at least one of the low-angle portions is provided in each unit segment which is equivalent to one turn of the spiral member about the rotation shaft, and an amount of a developer contained in the container space is enough to constantly bury one of the plurality of low-angle portions in the developer under a condition that the axial direction of the rotation shaft is held to be horizontal inside the container space.

4. The developer container according to claim 3 , wherein the amount of the developer contained in the container space is not enough to bury whole of the conveyance member in the developer.

5. A developer container comprising:

a container chamber that has a container space for containing a developer; and

a conveyance member having a rotation shaft and a spiral member which rotates inside the container space about the rotation shaft as a rotation center, the spiral member including a plurality of high-angle portions and a plurality of low-angle portions, the spiral member being spirally extended to an axial direction of the rotation shaft, angles of spirally extending directions of each of the plurality of high-angle portions to the axial direction being a first angle, angles of spirally extending directions of the plurality of low-angle portions to the axial direction being a second angle, which is smaller than the first angle,

wherein at least one of the low-angle portions is provided in each unit segment which is equivalent to one turn of the spiral member about the rotation shaft, and an amount of a developer contained in the container space is enough to constantly bury one of the plurality of low-angle portions in the developer under a condition that the axial direction of the rotation shaft is held to be horizontal inside the container space,

wherein:

the container space has a cylindrical shape,

when the conveyance member is contained in the container space, an outer circumference of the spiral member is arranged to fit within an inner circumference of the container space,

an angle of approximately 180 degrees is held between perpendicular lines extended to the rotation shaft respectively from centers of adjacent two of the plurality of low-angle portions, and

an amount of the developer contained in the container space is enough to occupy half or more of a total volume of the container space.

6. The developer container according to claim 5 , wherein the amount of the developer contained in the container space is enough to constantly bury both of the adjacent two of the plurality of low-angle portions in the developer.

7. The developer container according to claim 5 , wherein the amount of the developer contained in the container space is not enough to bury whole of the conveyance member in the developer.