Collected developer conveying device and image forming apparatus which vents a developing container

1. A collected developer conveying device comprising:

a conveying passage through which collected developer is conveyed;

a conveying member that is disposed in the conveying passage, and conveys the developer in the conveying passage by rotation thereof;

a developer carrying body that holds developer on a surface thereof, and that is rotatable; and

a ventilation passage through which air passes from a developing container that includes the developer carrying body,

wherein:

the conveying member defines a conveying cylinder in which the conveying member rotates,

the conveying passage includes an air flow region which is a region defined between the conveying cylinder and a portion of an outer boundary of the conveying passage which is provided above a rotational center of the conveying member in a gravitational direction and provided in a side of the conveying passage in which the conveying member rotates from an upper part of the conveying passage to a lower part thereof in the gravitational direction,

the conveying passage includes a second region which is a region defined between the conveying cylinder and a portion of an outer boundary of the conveying passage which is provided below a rotational center of the conveying member in a gravitational direction and provided in a side of the conveying passage in which the conveying member rotates from an upper part of the conveying passage to a lower part thereof in the gravitational direction, and

a sectional area of the air flow region, which is taken along a plane which is perpendicular to an axis around which the conveying member rotates, is larger than a sectional area, which is taken along the perpendicular plane, of the second region.

2. A collected developer conveying device comprising:

a conveying passage through which collected developer is conveyed;

a conveying member that is disposed in the conveying passage, and conveys the developer in the conveying passage by rotation thereof;

a developer carrying body that holds developer on a surface thereof, and that is rotatable; and

a ventilation passage through which air passes from a developing container that includes the developer carrying body,

wherein:

the conveying passage is connected to the ventilation passage,

a sectional region of the conveying passage located above a rotational center of the conveying member in a gravitational direction is divided by a perpendicular line that intersects a rotation-axis of the conveying member, and

a sectional area of a first side of the sectional region of the conveying passage, in which the conveying member rotates from an upper part of the conveying passage toward a lower part thereof in the gravitational direction, is larger than a sectional area of a second side of the sectional region of the conveying passage, in which the conveying member rotates from the lower part thereof toward the upper part thereof in the gravitational direction.

3. The collected developer conveying device as claimed in claim 1 , further comprising:

a loosening member that is disposed in an inflow passage of the collected developer in the conveying passage, and loosens the developer in the inflow passage,

wherein:

the air flow region is formed farther away from the rotational center of the conveying member than the loosening member in a horizontal direction.

4. The collected developer conveying device as claimed in claim 3 ,

wherein:

the ventilation passage is formed farther away from the rotational center of the conveying member than the loosening member in the horizontal direction.

5. The collected developer conveying device as claimed in claim 1 , further comprising:

a loosening member that is disposed in an inflow passage of the collected developer in the conveying passage, and loosens the developer in the inflow passage,

wherein

a first side of the loosening member, in which the conveying member rotates from the lower part of the conveying passage toward the upper part thereof in the gravitational direction, is formed larger in a horizontal direction than a second side thereof, in which the conveying member rotates from the upper part thereof toward the lower part thereof in the gravitational direction.

6. The collected developer conveying device as claimed in claim 1 , further comprising:

a loosening member that is disposed in an inflow passage of the collected developer in the conveying passage, and loosens the developer in the inflow passage,

wherein

a first side of the loosening member, in which the conveying member rotates from the upper part of the conveying passage toward the lower part thereof in the gravitational direction, is formed larger in a horizontal direction than a second side thereof, in which the conveying member rotates from the lower part thereof toward the upper part thereof in the gravitational direction.

7. The collected developer conveying device as claimed in claim

wherein

the loosening member is formed only in a side of the conveying passage in which the conveying member rotates from the lower part of the conveying passage toward the upper part thereof in the gravitational direction.

8. The collected developer conveying device as claimed in claim 1 , further comprising:

a loosening member that is divided in a horizontal direction into loosening member portions, is disposed in an inflow passage of the collected developer in the conveying passage, and loosens the developer in the inflow passage,

wherein:

the loosening member portions are arranged to be separated from each other in the horizontal direction, and

an area of the loosening member that is overlapped with the conveying passage in a first side thereof, in which the conveying member rotates from the lower part of the conveying passage toward the upper part thereof in the gravitational direction, is larger than an area of the loosening member that is overlapped with the conveying passage in a second side thereof, in which the conveying member rotates from the upper part thereof toward the lower part thereof in the gravitational direction.

9. The collected developer conveying device as claimed in claim 2 , further comprising:

a discharge passage in which the ventilation passage is formed, the ventilation passage passing developer discharged from the developing container and passing air from the developing container to the conveying passage,

wherein,

in a sectional region of the discharge passage in a section perpendicular to the rotation-axis direction of the conveying member, a sectional area thereof on a downstream side in a developer conveying direction of the conveying member is larger than a sectional area thereof on an upstream side in the developer conveying direction thereof.

10. The collected developer conveying device as claimed in claim 9 ,

wherein

the discharge passage is inclined so that the bottom surface thereof becomes gradually lower from the upstream side to the downstream side in a conveying direction of the conveying member.

11. The collected developer conveying device as claimed in claim 9 , further comprising:

an inflow passage through which the collected developer flows from a cleaner for removing developer remaining on a surface of an image carrying body,

wherein:

the inflow passage is connected to the second side of the sectional region of the conveying passage, and

the developer discharge passage is connected to the first side of the sectional region of the conveying passage.

12. The collected developer conveying device as claimed in claim 1 , further comprising:

an air intake unit that is connected to an air inlet of the developer collecting container, and draws air in the developer collecting container.

13. An image forming apparatus comprising:

an image carrying member in which a latent image is formed on a surface thereof;

a developing device that develops the latent image of the image carrying member into a visible image;

a transfer device that transfers the visible image of the image carrying body surface to a medium;

a cleaner that removes developer remaining on the image carrying body surface after the visible image is transferred to the medium;

a collected developer conveying device according to claim 1 that collects the developer collected by the cleaner; and

a fixing device that fixes the visible image of the medium surface.

14. The image forming apparatus as claimed in claim 13 ,

wherein:

the collected developer conveying device comprises:

a loosening member that is disposed in an inflow passage of the collected developer in the conveying passage, and loosens the developer in the inflow passage, and

the air flow region is formed farther away from the rotational center of the conveying member than the loosening member in a horizontal direction.

15. The image forming apparatus as claimed in claim 13 ,

wherein:

the ventilation passage is formed farther away from the rotational center of the conveying member than the loosening member in the horizontal direction.

16. The image forming apparatus as claimed in claim 13 ,

wherein

the collected developer conveying device comprises:

a loosening member that is disposed in an inflow passage of the collected developer in the conveying passage, reciprocates to intermittently come in contact with the conveying member being rotating, and loosens the developer in the inflow passage, and

a first side of the loosening member, in which the conveying member rotates from the lower part of the conveying passage toward the upper part thereof in the gravitational direction, is formed larger in a horizontal direction than a second side thereof, in which the conveying member rotates from the upper part thereof toward the lower part thereof in the gravitational direction.