Patent ID: 8827395

Claim:
An image forming apparatus, comprising: a recording head configured to discharge a droplet; a head tank configured to contain a liquid fed to the recording head; a carriage configured to mount the recording head and the head tank; a main tank configured to contain the liquid fed to the head tank; a liquid feeder configured to feed the liquid from the main tank to the head tank; and a feed controller configured to control feeding of the liquid from the main tank to the head tank, wherein the head tank comprises a displacement member configured to be displaced according to an amount of the liquid remaining therein; the carriage comprises a first detector configured to detect the displacement member; and the image forming apparatus comprises a second detector configured to detect the displacement member, wherein a first position of the displacement member detected by the first detector is a position when an amount of the liquid remaining in the head tank is less than that thereof remaining therein at a second position of the displacement member detected by the second detector, and the feed controller detects a displacement amount of the displacement member between the first and second positions, holds a difference displacement amount or a difference feed amount equivalent thereto, which is determined by reducing a predetermined displacement amount from the detected displacement amount, starts feeding the liquid from the main tank to the head tank after the displacement member is displaced in a direction of decrease of the liquid amount remaining in the head tank and a consumption of the liquid in the head tank after the first detector detects the displacement member becomes a predetermined liquid consumption, and feeds the liquid to the head tank in the difference feed amount equivalent to the difference displacement amount after the displacement member is displaced in a direction of increase of the liquid amount remaining in the head tank and the first detector detects the displacement member.