Patent ID: 7178911

Claim:
An ink cartridge, comprising: a cartridge case; an ink chamber situated within the cartridge case; an ink supply opening formed in the cartridge case for supplying ink from the ink chamber to an exterior of the cartridge; and a lever mechanism provided in the ink chamber, the lever mechanism including a light blocking member at a first end of the lever mechanism, the lever mechanism being rotatable about a rotation point on the lever mechanism, and the light blocking member being movable in association with rotation of the lever mechanism; wherein: the cartridge case includes at least a first side wall, a second side wall and a third side wall, the first wall being opposite from the second side wall and the third side wall extending from the first side wall to the second side wall; the ink chamber is situated within at least the first side wall, the second side wall and the third side wall; the third side wall includes a protrusion extending away from the third side wall, the protrusion including an interior space that opens into the ink chamber; the light blocking member is moveable between a first position and a second position in association with rotation of the lever mechanism; at least the first position is located in the interior space of the protrusion; the cartridge case has a first width from the first side wall to the second side wall and a second width from a first side wall-side of the protrusion to a second side wall-side of the protrusion; and the first width is greater than the second width.