Patent attributes
An ink tank including a reservoir for holding ink, the reservoir including a flexible wall for adjusting an internal volume of the reservoir; a biasing element for applying a force to the flexible wall that tends to increase the internal volume of the reservoir; an ink supply port for delivering ink from the reservoir to a printhead; and a breather element, at least a portion of which is disposed inside the reservoir, including a capillary material in contact with ink in the reservoir, wherein the breather element is configured to allow air to enter the reservoir in response to an internal pressure of the reservoir being less than atmospheric pressure outside the ink tank by an amount that is related to a property of the biasing element and a capillary pressure of the breather element.
