US Patent 7558494 Image forming apparatus

An image forming apparatus includes a developer reservoir, a detector, a computing section, a display unit, and a controller. The developer reservoir holds developer therein. The detector detects when the developer decreases to a first amount (i.e. toner-low level) The computing section computes current accumulated developer usage. The current accumulated developer usage is displayed on the display unit. The controller controls the display unit to display the current accumulated developer usage. When the detector detects the first amount, the controller controls the display unit to display a first value of the current accumulated developer usage that has been consumed until the first amount is detected.