Patent ID: 6533403
Filing Date: 2003-03-18
Classification: B41J

Abstract:
An ink reservoir comprising:a housing with an ink reservoir for storing ink, the housing having a first vent, a second vent, and an opening, the opening installed at a bottom end of the housing and connected to the ink reservoir; an air bag installed in the ink reservoir and connected to the first vent, the first vent enabling external air to enter into the air bag, the air bag adjusting internal pressure within the ink reservoir; an elastic constraining device installed in the ink reservoir for constraining air in the air bag to prevent the ink in the ink reservoir from leaking through the opening; a plugging device for plugging the second vent of the housing; and an active shaft movably installed in the ink reservoir and connected to the plugging device for pulling the plugging device out of the second vent of the housing; wherein comsumption of the ink in the ink reservoir causes the air bag to expand, and when the air bag expands to a predetermined degree, the air bag moves the active shaft, the active shaft pulls the plugging device out of the second vent, and air enters into the ink reservoir through the second vent to reduce the volume of the air bag, and when the air bag stops moving the active shaft, the active shaft returns to an original position and the plugging device plugs the second vent.