Image Forming Apparatus and Method of Controlling the Same

A method of controlling an image forming apparatus comprising:

• a photoconductor;
• a developing device including a developing roller configured to form a developer image on the photoconductor;
• a developer storage storing developer;
• and a supplier configured to supply the developer stored in the developer storage to the developing device, the method comprising:
• a first supplying step of supplying the developer stored in the developer storage to the developing device by operating the supplier by a first driving amount when a usage amount of the developer from a time point of beginning of use of the developer storage is smaller than a predetermined value;
• and
• a second supplying step of supplying the developer stored in the developer storage to the developing device by operating the supplier by a driving amount greater than the first driving amount when the usage amount of the developer from the time point of beginning of use of the developer storage is greater than or equal to the predetermined value.

An image forming apparatus, comprising:

• a developing device including a developing roller;
• a toner cartridge storing developer, the toner cartridge including a screw auger;
• and
• a controller configured to, when performing a printing operation, execute
• a usage-amount obtaining process of obtaining a usage amount of the developer,
• a first supplying process of supplying the developer stored in the toner cartridge to the developing device by operating the screw auger by a first driving time every time the usage amount becomes greater than or equal to a first threshold, and
• a second supplying process of supplying the developer stored in the toner cartridge to the developing device by operating the screw auger by a driving time longer than the first driving time when the usage amount of the developer from a time point of beginning of use of the toner cartridge becomes greater than or equal to a second threshold that is greater than the first threshold.