Patent ID: 8851596

Claim:
An image forming apparatus comprising: an apparatus body; a recording head to eject droplets of liquid; a head tank mounted to the recording head to store the liquid therein and supply the liquid to the recording head, a displacement member disposed at the head tank and displaceable with a remaining amount of the liquid in the head tank; an air release unit disposed at the head tank to open an interior of the head tank to an atmosphere; a main tank removably mounted to the apparatus body to store the liquid therein and supply the liquid to the head tank; a liquid feed device to feed the liquid from the main tank to the head tank; a body-side detector disposed at the apparatus body to detect the displacement member; a supply controller to control the liquid feed device to supply the liquid from the main tank to the head tank; wherein the supply controller controls a normal fill position acquisition operation to open the air release unit, feed the liquid to the head tank with the interior of the head tank open to the atmosphere, discharge a predetermined amount of the liquid from the head tank, detect with the body-side detector a current position of the displacement member after the predetermined amount of the liquid is discharged from the head tank, and retain the detected current position of the displacement member as a normal fill position, wherein the supply controller further controls a normal filling operation to start feeding the liquid from the main tank to the head tank without opening the air release unit when a consumption amount of the liquid in the head tank is a threshold amount or greater, and stop feeding the liquid from the main tank to the head tank when the body-side detector detects an arrival of the displacement member at the normal fill position, and wherein, when the body-side detector detects the displacement member at a start of the normal filling operation, the supply controller corrects the normal fill position to a position at which the liquid feed device can feed the liquid to the head tank.