151 a drainpipe inlet 152 formed in the housing 151 and a transferring bar 250 installed inside the housing 151 in a horizontal direction direction u2018 a u2019 indicated by an arrow the drainpipe inlet 152 is formed in an upper surface of the housing 151 and a drainpipe 210 of the fitting unit 100 is withdrawn from or inserted into the drainpipe inlet 152 as shown in fig4 and 5 the transferring bar 250 is moveably installed in an inner upper portion of the ink cartridge 150 in the horizontal direction and includes a first end 251 protruding toward the door 112 as shown in fig4 and a second end 252 moving together with a coupling member 260 of the fitting unit 200 that will be described later referring to fig2 the ink cartridges 150 respectively store different color inks such as yellow y magenta m cyan c and black b in spaces enclosed by the housings 151 and supply the different color inks to the developing units 160 respectively fig4 is an enlarged elevational view in partial cross section of the coupling of the developing unit 160 the ink cartridge 150 and the fitting unit 200 of fig2 referring.