Patent ID: 9523954
Filing Date: 2016-12-20
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: a photosensitive member; an exposure unit configured to expose the photosensitive member based on image data to form an electrostatic latent image; a developing unit configured to develop the electrostatic latent image using toner; a container configured to contain toner; a replenishment unit configured to replenish the toner to the developing unit from the container; a detection unit configured to detect an amount of the toner contained in the developing unit: a calculation unit configured to calculate a difference value between the amount of the toner detected by the detection unit and a target toner amount an accumulation unit configured to accumulate the difference value calculated by the calculation unit; a controller configured to control the replenishment unit based on the difference value calculated by the calculation unit and the accumulated value accumulated by the accumulation unit: and a determination unit configured to obtain an amount of toner consumed by the developing unit based on the image data, obtain the amount of toner contained in the developing unit based on a detecting result of the detection unit, determine, based on the amount of the consumed toner and the amount of the contained toner, whether or not an error of an amount of the toner replenished by the replenishment unit is larger than a threshold value, and determine, based on the number of times that the error is determined, whether or not replacement of the container is required.