Image forming apparatus and image forming system with display of remaining toner amount

An image forming system comprising:

• a toner container configured to accommodate toner;
• and
• an image forming apparatus to which the toner container is mountable, the image forming apparatus including:
• a mounting portion to which the toner container is to be capable of being mounted;
• an accommodating portion configured to accommodate the toner supplied from the toner container mounted on the mounting portion;
• a remaining toner amount detecting portion configured to output an output value on the basis of a toner amount of the toner accommodated in the accommodating portion;
• a display portion configured to perform a remaining toner amount display on the basis of the output value outputted from the remaining toner amount detecting portion, wherein a state of the display portion changes from a first state to a second state different from the first state by the toner being supplied in a predetermined amount or more from the toner container to the accommodating portion;
• and
• a controller configured to control the display portion, wherein
• (i) when a supplying operation for supplying the toner from the toner container to the accommodating portion is performed, the controller sets a threshold on the basis of a first output value outputted from the remaining toner amount detecting portion before the toner is supplied from the toner container to the accommodating portion, and
• (ii) the controller discriminates whether or not the toner in the predetermined amount or more is supplied to the accommodating portion by comparing the threshold with a second output value outputted from the remaining toner amount detecting portion after the toner is supplied from the toner container to the accommodating portion,
• wherein the threshold is a value between the first output value and a third output value outputted from the remaining toner amount detecting portion in a case in which the toner accommodated in the toner container that has never been used is supplied to the accommodating portion before supply of the toner, and is closer to the third output value than to the first output value.