Image forming apparatus and developer supply device that is detachable from and attachable to the image forming apparatus

A developer supply device for supplying developer contained in a developer container toward a developing device in an apparatus body of an image forming apparatus, the developer supply device comprising:

• a conveyance passage to deliver the developer discharged from the developer container;
• a developer receptacle detachable and attachable with respect to the developer container;
• a sub-hopper detachable and attachable with respect to the developing device, the sub-hopper to store the developer discharged toward the developing device;
• a controller configured to receive information of a detection of a shortage from the developing device and control the sub-hopper to supply the developer toward the developing device in response to the detection of the shortage;
• a conveying tube having flexibility, the conveying tube having a first end portion coupled to the developer receptacle and a second end portion coupled to the sub-hopper, the conveying tube to convey the developer from the developer receptacle to the sub-hopper;
• and
• a holder including a shaft and configured to hold the conveying tube in the developer receptacle or the sub-hopper, wherein
• the developer supply device is detachable from and attachable to the apparatus body of the image forming apparatus with a connection among the developer receptacle, the sub-hopper, and the conveying tube being maintained, and
• the holder is configured to wind a part of the conveying tube.