Image Number 7 for United States Patent #7894730.
An image forming apparatus includes: an image forming unit; a containing unit; two detecting units; a counting unit; and a determining unit. The image forming unit is configured to form a toner image. The containing unit is configured to contain waste that is generated when the image forming unit forms a toner image. The two detecting units that are configured to detect the waste accumulated in the containing unit. The counting unit starts, when at least one of the two detecting units detects waste, counting up a count value based on the toner image forming operation executed by the image forming unit. The determining unit determines that waste accumulated in the containing unit has reached a maximum amount if the count value of the counting unit is equal to or greater than a predetermined first threshold value and both of the two detecting units detects waste.