Image forming apparatus and control method of image forming apparatus to replenishment control of toner

A control method of an image forming apparatus which includes an image carrier, a latent image forming unit configured to form an electrostatic latent image on the image carrier based on image data, a development unit configured to develop the electrostatic latent image using a developer including a toner, a detection unit configured to detect an amount of the toner in the development unit, a portion to which a container is mountable, the container containing a toner, and a replenishment unit configured to replenish toner to the development unit from the container on which the portion is mounted, the control method comprising:

• determining a first value based on the image data, the first value being corresponded to an amount of toner consumed from the development unit for forming an image;
• determining a second value, the second value being corresponded to a difference between the amount of the toner detected by the detection unit and a target amount of the toner;
• determining a third value by accumulating the second value;
• determining an amount of toner to be replenished to the development unit based on the first value, the second value and the third value;
• determining a cumulative value by accumulating the amount of toner;
• controlling the replenishment unit based on the cumulative value;
• and
• setting, in a case where the container is exchanged with another container, the third value as a predetermined value without changing the cumulative value into the predetermined value.