Patent ID: 7991308

Claim:
An image forming apparatus, comprising: a printing medium supply unit to supply a printing medium; an image forming unit to form a toner image onto the printing medium supplied from the printing medium supply unit; a waste toner bottle to contain a waste toner collected from the image forming unit, an auger to level the waste toner contained in the waste toner bottle, and a motor which rotates the auger; and a waste toner amount detecting apparatus which detects an amount of the waste toner contained in the waste toner bottle, comprising: a motor current detector to detect a drive current of the motor which rotates the auger for leveling the waste toner contained in the waste toner bottle; and a controller which comprises a determining unit to determine whether the waste toner bottle is full of the waste toner using a difference between a first current value corresponding to a minimum drive current of the motor and a second current value corresponding to the detected drive current of the motor.