Patent ID: 7364279

Claim:
An ink-jet printer, comprising: a printing head for performing printing on a print medium by ejecting ink from nozzles; an ink tank for storing the ink to be supplied to the printing head; an ink passage through which the ink is supplied from the ink tank to the printing head; a buffer tank which stores the ink supplied through the ink passage; and an air-discharging device which discharges an air accumulated in the buffer tank through an air-discharge passage and which includes a valve member operable to open and close a communication opening that is provided in the air-discharge passage a part of which functions as a valve chamber, the valve member having (a) a valve portion which opens and closes the communication opening and which includes a sealing member and (b) a rod portion connected to the valve portion, wherein the air-discharging device further includes air-discharge-flow assuring means for assuring a discharge flow of the air flowing from the buffer tank through the air-discharge passage, wherein the air-discharge-flow assuring means is realized by a structure that the air-discharging device includes retaining means for retaining the sealing member on the rod portion such that the sealing member is movable together with the rod portion in a direction to open and close the communication opening, and wherein the sealing member is an annular member inserted on the rod portion, and the valve member includes rotation preventive means provided between the rod portion and the sealing member for preventing the rod portion and the sealing member from rotating relative to each other.