Abstract: A valve unit 36 is placed in an ink flow passage 35 between an ink cartridge 8 and a recording head 7 and can be controlled in association with the cleaning operation of the recording head 7. Under the control of a drive controller, the valve unit 36 holds for a predetermined time a state in which negative pressure produced by a suction pump is accumulated, and is opened after the expiration of the predetermined time or is opened with the negative pressure accumulated and driving the suction pump is continued. The air bubbles remaining in a stuck state in the ink flow passage can be peeled from the ink flow passage together with an instantaneous fast ink flow produced as the valve unit 36 is opened, and the peeled air bubbles can be discharged, effectively from the ink flow passage following the subsequent ink flow.

Abstract: A plurality of recording engines 3, 3′, each including an ink jet recording head 1 mounted on a carriage 2, which ejects an ink droplet onto a recording sheet to perform printing are arranged such that recording sheets are feed able via different feeding paths 4, 4′. Ink is supplied from a main tank common to the respective recording engines 3, 3′. A controller 10 compares an amount of an externally provided print data with an amount of a reference data. The controller divides the print data into data sets, each responding to a predetermined amount of page, and provides the data sets the plural recording engines, when the print data amount exceeds the reference data amount. The controller operates a single recording engine en the print data amount is less than the reference data amount.

Abstract: The ink-jet recording apparatus according to the invention is provided with a recording head for jetting an ink droplet corresponding to print data, a main tank for supplying ink to the recording head and a subtank composed of upper and lower two tanks respectively connected to the main tank and the recording head and mutually communicating, the upper tank of the subtank is formed by an ink tank having an ink outlet for leading ink to the recording head, and the lower tank is formed by an ink tank having an ink inlet for leading ink from the main tank by pressure of a pump and elastically deformable according to the variation of internal pressure.

Abstract: In an ink jet recording apparatus, at least one main tank stores ink therein. A plurality of subtanks are communicated with each main tank. Each subtank stores ink supplied from the main tank. Each subtank is communicated with at least one recording head.

Abstract: In a tube pump, a rotor is fixed to a drive shaft so as to rotate therewith. A tube pressing member is swingable in an axial direction of the drive shaft. A swinging member swings the tube pressing member in accordance with the rotation of the rotor. An upper outer face of a tube is fixed to a lower portion of the tube pressing member. A lower outer face of the tube is fixed to a fixing member. The tube is forcibly pressed and expanded in accordance with the swing motion of the tube pressing member, while the pressed/expanded part is shifted in an extending direction.