Patent ID: 8894169
Filing Date: 2014-11-25
Classification: B41J

Abstract:
1. A method for controlling an image forming apparatus comprising a sub tank to store liquid to be supplied to a recording head, a carriage mounting the recording head and the sub tank, a main tank to store the liquid to be supplied to the sub tank, a liquid feed device to supply the liquid from the main tank to the sub tank, and a displacement member provided at the sub tank and displaceable with a remaining amount of the liquid in the sub tank, the method comprising: detecting, by a first detector mounted on the carriage, a first position of the displacement member; detecting, by a second detector mounted on the apparatus body, a second position of the displacement member; detecting and retaining, by a detection retainer, a differential supply amount corresponding to a first displacement amount of the displacement member between the first position and the second position or a second displacement amount obtained by subtracting a predetermined displacement amount from the first displacement amount; providing a liquid consumption amount measuring device to receive a detection output of the first detector and measure a consumption amount of the liquid in the sub tank when the displacement member displaces from the first position in a direction in which the consumption amount of the liquid in the sub tank decreases; starting, by a supply controller, supply of the liquid from the main tank to the sub tank without using the second detector, when the consumption amount of the liquid measured by the liquid consumption amount measuring device reaches a predetermined threshold value, and supplying the liquid by the differential supply amount after the first detector detects the displacement member; and controlling by the supply controller, when the first position of the displacement member is detected with the first detector, and the remaining amount of the liquid in the sub tank is smaller than when the second position of the displacement member is detected with the second detector, the liquid consumption amount measuring device to start measuring the consumption amount of the liquid in the sub tank, after a detection output of the first detector continues to be, for a predetermined time, in a detection state in which the first detector detects the displacement member, then shifts from the detection state to a non detection state in which the first detector does not detect the displacement member, and continues to be in the non detection state for a second predetermined time.