Patent ID: 8752923

Claim:
An image forming apparatus comprising: an apparatus main body; a recording head discharging liquid droplets; a sub tank containing liquid to be supplied to the recording head; a carriage on which the recording head and the sub tank are mounted; a main tank containing liquid to be supplied to the sub tank; and a fluid feeding unit performing fluid supply from the main tank to the sub tank, wherein the sub tank includes a displacement member to be displaced depending on a remaining amount in the sub tank, the carriage includes a first detecting unit detecting that the displacement member is at a predetermined first position, the apparatus main body includes a second detecting unit detecting that the displacement member is at a predetermined second position, the remaining amount at the predetermined first position is less than the remaining amount at the predetermined second position, the image forming apparatus further includes a control section that detects and stores a differential supply amount corresponding to a displacement amount of the displacement member, the displacement amount corresponding to a difference between a position detected by the first detecting unit and a position detected by the second detecting unit, and the control section performs control to supply the differential supply amount of liquid to the sub tank after the first detecting unit detects the displacement member n a case here liquid is supplied from the main tank to the sub tank without using the second detecting unit.