Patent ID: 6494553
Filing Date: 2002-12-17
Classification: B41J

Abstract:
In an ink printer having a printhead, an ink container connected to the printhead for supplying ink to the printhead, and an ink level sensor for measuring the quantity of ink in the ink container, a method of determining when the ink level sensor should measure the quantity of ink in the ink container, the method comprising:measuring the quantity of ink ejected by the printhead; periodically determining if the quantity of ink ejected by the printhead has exceeded a first predetermined threshold; if the quantity of ink ejected by the printhead has exceeded the predetermined threshold, performing a first ink level measurement comprising measuring the quantity of ink in the ink container; periodically after the first ink level measurement, determining if the quantity of ink ejected by the printhead since an immediately preceding ink level measurement has exceeded a second threshold; and if the quantity of ink ejected by the printhead since the immediately preceding ink level measurement has exceeded the second threshold, performing an additional ink level measurement comprising measuring the quantity of ink in the ink container.