Patent ID: 8240832

Claim:
A head unit to which ink is supplied from a storage tank and from which ink thereinside is returned to said storage tank in an inkjet printer, comprising: a plurality of heads each having a plurality of nozzles arranged in an arrangement direction, for ejecting fine droplets of ink from said plurality of nozzles; a supply tank storing ink above said plurality of heads; an ink inlet part for running ink into said plurality of heads from said supply tank, wherein said ink inlet part includes a plurality of ink pipes each having the same length and the same passage diameter and extending straight downwardly from said supply tank to be connected to said plurality of heads; a collecting part having an internal space into which ink flows from said plurality of heads; and an ink outlet part connecting said plurality of heads and said collecting part, wherein said ink outlet part includes a plurality of ink outlet pipes having the same length and the same passage diameter and extending straight downwardly from said collecting part to be connected to said plurality of heads, wherein said collecting part is positioned between said plurality of heads and said supply tank and has a shape configured to avoid interference with said plurality of ink inlet pipes, or said supply tank is positioned between said plurality of heads and said collection part and has a shape configured to avoid interference with said plurality of ink outlet pipes.