Patent ID: 7748808

Claim:
A droplet ejection apparatus comprising: a plurality of tanks, wherein each of the plurality of tanks are capable of storing a different kind of basic liquid; a plurality of sub-tanks, including a first sub-tank that includes a mixed liquid of two or more of the different kinds of the basic liquids from the plurality of tanks; a replenishment amount detector that detects amount of each of the different kinds of the basic liquids to be transferred to the first sub-tank; a liquid replenisher that transfers the basic liquids stored in the tanks into the sub-tanks until a predetermined amount for each of the basic liquids is detected by the replenishment amount detector; and a recording head ejecting the liquids supplied from the sub-tanks in a form of droplets; wherein the replenishment amount detector provides a signal based on amount of liquid existing in the first sub-tank; wherein the replenishment amount detector provides a signal; wherein at a first detection point, indicating that the liquid amount of the first sub-tank reaches a first amount which requires an operation to start replenishing the basic liquids to the first sub-tank; wherein at a second detection point, indicating that the liquid amount of the first sub-tank reaches a second amount which does not require replenishing the basic liquids; and wherein at a third detection point, indicating that the liquid amount of the first sub-tank reaches a third amount which is determined by dividing a difference between the first amount and the second amount by a ratio of the basic liquids to be mixed.