Patent ID: 7954937

Claim:
An ink jet printing apparatus constructed to print an image on a printing medium with a movement of a carriage on which a head cartridge is detachably mounted, wherein the head cartridge has an ink tank replaceably mounted thereon and is equipped with a printing head for ejection of ink supplied from the ink tank, the ink jet printing apparatus comprising: a carriage side connecting portion, which is provided in the carriage, forming a transmission route of a control signal of the printing head, and being connected by pressure contact with a head cartridge side connecting portion provided in the head cartridge; a pressure contact means for connecting the head cartridge side connecting portion and the carriage side connecting portion by pressure contact when the head cartridge is mounted on the carriage; a locking member movable between a first position in which the head cartridge is fixed to the carriage and a second position in which the head cartridge is detachably mounted on the carriage, wherein the locking member is prevented from moving to the second position from the first position by the ink tank when the ink tank is mounted on the head cartridge, and is not prevented from moving to the second position from the first position when the ink tank is not mounted on the head cartridge.