Collected developer conveying device and image forming apparatus

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 relatable;
• and
• a ventilation passage through which air passes from a developing container including the developer carrying body,
• wherein
• the conveying passage is connected to the ventilation passage, and,
• in a case where a sectional area of the conveying passage upper than a rotational center of the conveying member in a gravitational direction is divided by a perpendicular line including a rotation-axis, a sectional area thereof on a first side 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 thereof on a second side of the conveying passage, in which the conveying member rotates from the lower part thereof toward the upper part thereof in the gravitational direction.