Patent ID: 7726787

Claim:
An ink jet recording apparatus comprising: an ink cartridge configured to store ink, the ink cartridge including a discharge port configured to discharge the ink, and an atmospheric-pressure introducing port configured to introduce an atmospheric pressure to an inside of the ink cartridge; an image forming unit configured to form an image on a recording medium by ejecting the ink supplied from the ink cartridge to the recording medium; a cartridge casing configured to hold the ink cartridge therein, the cartridge casing including an atmospheric-pressure introducing sleeve having a distal end projecting to outside, the atmospheric-pressure introducing sleeve communicating with the atmospheric-pressure introducing port of the ink cartridge; an elbow-shaped flow passage forming unit attached to the cartridge casing, the elbow-shaped flow passage forming unit including an ink inlet port communicating with the discharge port and an ink outlet port opening toward the atmospheric-pressure introducing sleeve, the ink inlet port communicating with the outlet port via an approximately L shaped ink flow passage; and a flexible ink tube connecting the ink outlet port and the image forming unit, the ink tube being arranged to pass a position offset from the atmospheric-pressure introducing sleeve along an outer wall of the cartridge casing and extend toward the image forming unit.