Inkjet recording apparatus

#This application claims the benefit of Japanese Patent Application No. 2005-217697 filed Jul. 27, 2005 in the Japanese Patent Office, the disclosure of which is incorporated herein by reference.

#The present invention relates to a technique for performing transfer of at least one of ink and air existing at least in a tube, which connects an ink tank and a recording head in an inkjet recording apparatus, regardless of variations in dimension corresponding values of the tube (for example, a diameter of the tube, a length of the tube, an inner volume of the tube, a flow path resistance in the tube (a pressure loss)), in a manner in accordance with the variations in the dimension corresponding values of the tube.

#There is a known inkjet recording apparatus provided with an ink supply system of tube supply type. Specifically, such an inkjet recording apparatus includes a carriage and a main tank. On the carriage a recording head and a sub tank are mounted. The recording head ejects ink from an ejection nozzle to perform recording on a recording medium. The sub tank stores ink to be supplied to the recording head. The main tank stores ink to be supplied to the sub tank. In the inkjet recording apparatus, when the ink in the sub tank decreases, the ink in the main tank is supplied to the sub tank through a tube.

#A preferred embodiment of the present invention will be described hereinafter with reference to the drawings, in which:

#FIG. 1 is a perspective view showing an appearance of a preferred inkjet recording apparatus to which the present invention is applied;

#FIG. 2 is a cross-sectional view of the inkjet recording apparatus;

#An inkjet recording apparatus 1 is a so-called multifunction device (MFD: Multi Function Device) including a printer function, a copier function, a scanner function, a facsimile function and others. A sheet, such as a sheet of paper or a plastic film, is used as a recording medium. In the inkjet recording apparatus 1, black-and-white image recording is performed in the facsimile function, while color image recording and black-and-white image recording can be performed in the printer function and the copier function.

#As shown in FIG. 1 and FIG. 2, the inkjet recording apparatus 1 includes a scanner 2 over a case 1a and a recording unit 7 that performs recording (i.e., image formation) on a recording sheet 40 in each of the above functions under the scanner 2 (in an upper part inside the case 1a).

#As shown FIG. 2, a sheet feeder 30 is disposed in a lower part inside the case 1a. A box-shaped metal frame 5 is disposed above the sheet feeder 30 in a rear part inside the case 1a. The frame 5, which has a substantially rectangular configuration with a larger length in a right and left direction, is fixed inside the case 1a.