Patent ID: 7469992

Claim:
An ink supplying system, comprising: an ink cartridge having a joint section for supplying ink contained in the ink cartridge to an exterior and having an engage reference portion for serving as a reference position in installing the ink cartridge; an installation section in which the ink cartridge is installed; an engage portion provided on the installation section, the engage portion being structured to engage with the engage reference portion; and an ink drawing member having a predetermined positional relationship with the installation section, the ink drawing member being constructed for connection with the joint section to draw the ink from the ink cartridge, wherein when the ink cartridge is installed in the installation section, the engage reference portion engages with the engage portion to position the ink cartridge in the installation section so that the joint section is positioned for connection to and disconnection from the ink drawing member, after the ink cartridge is installed in the installation section, the joint section is connected to and disconnected from the ink drawing member by rotating the ink cartridge about a predetermined rotation center axis in the installation section, the joint section is positioned in the proximity of one end of the ink cartridge, the one end being farthest removed from the predetermined rotation center, the engage reference portion is positioned between the one end and a second end opposite to the one end of the ink cartridge, an outer face of the ink cartridge at which the engage reference portion is positioned, an outer face of the ink cartridge at which the joint section is positioned, and the one end, are all mutually differ and adjoin, and the distance L 1 between the joint section and the engage reference portion is shorter than the distance L 2 between the one end and the engage reference portion.