Abstract: An image forming apparatus includes a developer container having a movable wall therein, a determination unit, a movable wall driving unit, and a movable wall driving controller. The determination unit outputs first determination information when a number of outputs of a signal indicating that a detection sensor has detected a developer is less than a threshold value, and outputs second determination information when the number of outputs thereof is equal to or greater than the threshold value. The movable wall driving unit includes a first driving motor for moving the movable wall and a first driving circuit for controlling driving thereof. The movable wall driving controller includes a signal controller. The signal controller transmits a drive permission signal for the first driving motor when the first determination information is output, and transmits a drive non-permission signal for the first driving motor when the second determination information is output.

Abstract: A developer container includes a container main body having an internal space and a developer discharge port; a movable wall moving in the internal space toward the developer discharge port; a detection surface which is a part of an inner peripheral surface that divides a storage space of a developer in the container main body and which becomes a detection region of a first detection sensor which detects the developer in the storage space; and a rotating body arranged in the storage space and capable of rotating around a rotary shaft along the first direction. The rotating body is mounted with a cleaning member which cleans the detection surface, a stirring member which stirs a developer in the storage space, and a detection target member to be a detection target of a second detection sensor which detects presence of the container main body.

Abstract: An image forming apparatus includes a developer container having a movable wall therein, a determination unit, a movable wall driving unit, and a movable wall driving controller. The determination unit outputs first determination information when a number of outputs of a signal indicating that a detection sensor has detected a developer is less than a threshold value, and outputs second determination information when the number of outputs thereof is equal to or greater than the threshold value. The movable wall driving unit includes a first driving motor for moving the movable wall and a first driving circuit for controlling driving thereof. The movable wall driving controller includes a signal controller. The signal controller transmits a drive permission signal for the first driving motor when the first determination information is output, and transmits a drive non-permission signal for the first driving motor when the second determination information is output.

Abstract: A developer storage container includes a container body, a shaft, a moving wall and a pressing member. The container body has an inner peripheral surface defining a tubular internal space extending along a first direction. The shaft is arranged to extend in the first direction in the internal space and rotatably supported. The moving wall is movable in the first direction in the internal space while conveying the developer in the internal space toward a developer discharge port. The pressing member moves integrally with the moving wall by pressing the moving wall when the shaft is rotated in a first rotating direction and relatively moves to an upstream side with respect to the moving wall according to the engagement of a first engaging portion and a second engaging portion when the shaft is rotated in a second rotating direction opposite to the first rotating direction.