Patent ID: 7547097

Claim:
A liquid filling method for filling a continuous supply passage with a liquid supplied from a liquid container of a liquid ejection apparatus, the apparatus including the supply passage for supplying the liquid from the liquid container that retains the liquid to a nozzle for ejecting the liquid, wherein the supply passage includes tubular lines, a first enlarged portion and a second enlarged portion each communicating with the tubular lines, wherein each of the first and second enlarged portions has a width larger than a width of the tubular lines and traps bubbles when the supply passage is filled with the liquid, wherein the second enlarged portion is located closer to the nozzle than the first enlarged portion in the supply passage, wherein the method comprises: a first preliminary filling step for moving a front edge of the liquid to a first preliminary position defined as a position between the first enlarged portion and the second enlarged portion in the supply passage, thereby to preliminarily fill the first enlarged portion with the liquid; a second preliminary filling step for moving the front edge of the liquid to a second preliminary position defined as a position between the nozzle and the second enlarged portion, thereby to move the bubbles from the first enlarged portion toward the nozzle and preliminarily fill the second enlarged portion with the liquid; and a complete filling step for filling the supply passage entirely with the liquid subsequent to the second preliminary filling step, thereby to remove the bubbles trapped in the second enlarged portion through the nozzle.