Ink jet recording apparatus

An ink jet recording apparatus comprising:

• a plurality of ink cartridges each configured to store ink, a discharge port configured to discharge the ink, and an atmospheric-pressure introducing port configured to introduce an atmospheric pressure to an inside of a corresponding one of the ink cartridges, each ink cartridge having a profile formed in a flat shape;
• an image forming unit configured to form an image on a recording medium by ejecting the ink supplied from the ink cartridges to the recording medium;
• a cartridge casing configured to hold the ink cartridges therein in a state that flat surfaces of the ink cartridges face each other, the cartridge casing including a plurality of atmospheric-pressure introducing sleeves, each atmospheric-pressure introducing sleeve communicating with the atmospheric-pressure introducing port and having a distal end projecting to outside;
• an elbow-shaped flow passage forming unit attached to the cartridge casing, the elbow-shaped flow passage forming unit including a plurality of ink inlet ports communicating with the discharge ports of the ink cartridges and a plurality of ink cutlet ports opening toward the atmospheric-pressure introducing sleeves, wherein ink flow passages which allow the ink inlet ports and the ink outlet ports to communicate with each other are bent in an approximately L shape;
• and
• flexible ink tubes connecting the ink outlet ports and the image forming unit, wherein
• the ink tubes are arranged to extend toward the image forming unit while passing between the atmospheric-pressure introducing sleeves along an outer wall of the cartridge casing.

An ink jet recording apparatus comprising:

• an ink cartridge which includes a flat rectangular-parallelepiped-shaped ink tank portion filled with ink and having a widthwise size smaller than a size in other direction, a discharge port being formed in the ink tank portion in a direction perpendicular to the widthwise direction and configured to discharge the ink filled in the ink tank portion, and an atmospheric-pressure introducing port being formed in the ink tank portion in the same direction as the discharge port and configured to introduce an atmospheric pressure to the inside of the ink tank portion;
• 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 communicating with the atmospheric-pressure introducing port of the ink cartridge and having a distal end projecting to outside;
• 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, an ink outlet port opening toward the atmospheric-pressure introducing sleeve, and a substantially L-shaped flow passage, the ink inlet port communicating with the ink outlet port communicating with each other via the flow passage;
• and
• a flexible ink tube connecting the ink outlet port and the image forming unit, wherein
• the ink tube is arranged (or pulled around) to extend toward the atmospheric-pressure introducing sleeve along an outer wall of the cartridge casing, and
• the ink tube is arranged to extend toward the image forming unit while passing a position which corresponds to a corner portion of the ink tank portion as viewed in the projecting direction of the atmospheric-pressure introducing sleeve.

An ink jet recording apparatus comprising:

• a plurality of ink cartridges each including an ink tank portion filled with ink, a discharge port configured to discharge the ink filled in the ink tank portion, and an atmospheric-pressure introducing port configured to introduce an atmospheric pressure to an inside of the ink tank, each ink cartridge having a profile formed in a flat shape;
• an image forming unit configured to form an image on a recording medium by ejecting the ink supplied from the ink cartridges to the recording medium;
• a cartridge casing configured to hold the ink cartridges therein in a state that flat surfaces of the ink cartridges face each other, the cartridge casing including a plurality of atmospheric-pressure introducing sleeves, each atmospheric-pressure introducing sleeve communicating with the atmospheric-pressure introducing port and having a distal end projecting to outside;
• an elbow-shaped flow passage forming unit attached to the cartridge casing and including a plurality of ink inlet ports communicating with discharge ports of the ink cartridges and a plurality of ink outlet ports opening toward the atmospheric-pressure introducing sleeves, wherein ink flow passages which allow the ink inlet ports and the ink outlet ports to communicate with each other are bent in an approximately L shape;
• and
• flexible ink tubes connecting the ink outlet ports and the image forming unit, wherein
• the ink tubes are arranged to extend toward the image forming unit while passing positions corresponding to gaps between the atmospheric-pressure introducing sleeves along an outer wall of the cartridge casing.

An ink jet recording method comprising the steps of:

• arranging a plurality of ink cartridges each including an ink portion, an ink discharge portion and an atmospheric pressure introducing port in the inside of a cartridge casing;
• supplying ink to an image forming unit arranged above the cartridge casing from the ink cartridges by way of a plurality of ink tubes having flexibility;
• recording an image on a recording medium by ejecting the ink to the recording medium using the image forming unit, communicably connecting one end of the ink tube with the ink discharge portion by way of an approximately L-shaped ink flow passage formed in an elbow flow passage forming means;
• and
• arranging the ink tube above the ink discharge portion and, at the same time, extending upwardly along an outer wall of the cartridge casing while allowing the ink tube to pass between atmospheric-pressure introducing sleeves which are communicably connected with atmospheric-pressure introducing port in communicably connecting another end of the ink tube to the image forming unit.

An ink jet recording method comprising the steps of:

• taking out ink from a plurality of ink cartridges held in a cartridge casing, each ink cartridge configured to store ink and each cartridge casing configured to include atmospheric-pressure introducing sleeves projecting outside from an outer wall of the cartridge casing;
• turning a direction of flow of the ink upwardly by allowing the ink to pass through L-shaped ink flow passages formed in an elbow-shaped flow passage forming unit;
• supplying the ink to an image forming unit arranged above the cartridge casing from the L-shaped ink flow passages by way of flexible ink tubes such that the flexible ink tubes extend upwardly along the outer wall of the cartridge casing while passing between the atmospheric-pressure introducing sleeves;
• and
• ejecting the ink to a recording medium from the image forming unit.