Image forming apparatus

An image forming apparatus comprising:

• a body casing;
• a developing device including:
• a developing roller rotatable about a first axis extending in an axial direction;
• a casing including:
• a developing chamber positioned inside of the casing, the developing chamber configured to accommodate toner for supplying the developing roller;
• and
• a toner accommodation chamber positioned inside of the casing, the toner accommodation chamber configured to accommodate toner for supplying to the developing chamber;
• a coupling rotatable both in a first direction and in a second direction opposite to the first direction about a second axis extending in the axial direction, the coupling including a coupling gear;
• an auger or an agitator that configured to supply the toner in the toner accommodation chamber to the developing chamber and is rotatable about an auger axis extending in the axial direction;
• a transporting gear that is rotatable together with the auger or the agitator;
• and
• a moving gear that is in mesh with the coupling gear and is rotatable both in the first direction and the second direction about a third axis extending in the axial direction, the moving gear being movable while being in mesh with the coupling gear between a first position where the moving gear is in mesh with the transporting gear and a second position where the moving gear is out of mesh with the transporting gear, the moving gear moving to the first position when the coupling gear rotates in the first direction and to the second position when the coupling gear rotates in the second direction;
• a coupler engageable with the coupling;
• a motor configured to drive the coupler, the motor configured to cause the coupler to be a first state in which the coupling rotates in the second direction and a second state in which the coupling rotates in the first direction;
• and
• a controller configured to:
• determine whether the remaining toner amount in the developing chamber is less than or equal to a first predetermined value;
• send, from the controller to the motor, an instruction for changing the coupler to the second state, in a case where the controller judges that the remaining toner amount in the developing chamber is smaller than or equal to the first predetermined value.