Abstract: An ink cartridge has a first partitioning wall 5 and a third partitioning wall 7 for dividing the inside of a case 2 into a first ink chamber 9 and a second ink chamber 10, and a second partitioning wall 6 for demarcating an atmosphere connection chamber 11. In an upper case cover 3 are formed an ink filling hole 13 communicating with the second ink chamber 10 and a pressure reduction hole 14 communicating with the atmosphere connection chamber 11. Therefore, when ink filling is being done, the filling apparatus and the pressure reduction apparatus need only be brought to bear from one side of the upper case cover, resulting in improved work efficiency. Ink filling can be performed efficiently because the ink successively passes to the second ink chamber 10 and the first ink chamber 9. After ink filling, the ink filling hole 13 and the pressure reduction hole 14 can easily be sealed off with sealing material. An ink cartridge is thus provided that can be easily assembled at low cost.

Abstract: An ink cartridge has an ink tank in which the ink is stored, and a shutter mechanism which is arranged in the ink tank. The shutter mechanism includes a lever which is supported swingably and which has one end provided with a shutter and the other end provided with a float. The mass and the volume of the float are set so that the first direction, in which the lever moves by the buoyancy and the gravity generated when the entire shutter mechanism is positioned in the ink, is opposite to the second direction in which the lever moves by the buoyancy and the gravity when a part of the float protrudes from the ink liquid surface. A residual amount of an ink is indicated without being excessively affected by any disturbance such as the surface tension of the ink.

Abstract: An ink cartridge includes a container; an ink reservoir provided in the container; an opening provided in the container, the opening being situated in the container so that the opening can communicate with the ink reservoir through a fluid path; and a stop fitted in the opening, the stop having elasticity and being formed of a material such that a hollow needle can be penetrated through the stop. The stop is moveable between a first position permitting communication between the opening and the fluid path, and a second position in which the stop substantially obstructs communication between the opening and the fluid path.

Abstract: An ink cartridge includes at least one wall; an ink chamber capable of storing ink, the ink chamber being bounded, at least in part, by the at least one wall; an ink supply opening configured to permit communication between the ink chamber and an area outside of the ink chamber; and a detection portion. The detection portion extends away from the ink chamber relative to portions of the ink cartridge adjacent to the detection portion, at least when the ink cartridge is installed in an image forming apparatus; and at least one part of the detection portion is capable of obstructing at least a portion of a light beam directed through the detection portion.

Abstract: An ink cartridge includes a bottom wall, a first surface having a first intersection with the bottom wall, a second surface having a second intersection with at least one of the bottom wall and the first surface, an ink chamber bounded, at least in part, by the bottom wall, the first surface and the second surface, and an ink supply opening for supplying ink in the ink chamber to a location outside of the ink chamber, the ink supply opening being provided in the bottom wall. The first intersection has a first curvature and the second intersection has a second curvature and the first curvature is greater than the second curvature, and at least a portion of the first intersection is closer to the ink supply opening than at least a portion of the second intersection.

Abstract: An ink cartridge including: a casing having an ink chamber for storing the ink; and a plurality of projections projecting from an outer surface of the casing and spaced apart from each other. The plurality of projections preferably includes at least three projections which are arranged at substantially the same pitch. Each of the plurality of projections is preferably provided by a projecting plate which is elongated along the outer surface of the casing. A height of each of the plurality of projections is preferably is larger than a pitch between each adjacent pair of the plurality of projections. The plurality of projections are preferably formed integrally with the casing.