Patent ID: 7717540

Claim:
A clog detection and clearing method for an ink delivery system including a stationary primary ink supply, a moveable print head having an ink reservoir, a dynamic tube fluidly interconnecting the primary ink supply and the ink reservoir, and a reversible pump disposed to pump ink within the dynamic tube, comprising the steps of: a) pulling a volume of ink from the print head ink reservoir into the dynamic tube; b) allowing the volume of ink to remain in the dynamic tube for a time interval so as to potentially dissolve a clog at a suspected clog location therein; c) pulling the volume of ink toward an ink sensor proximal of the suspected clog location; and d) sensing with the ink sensor whether the volume of ink has reached the ink sensor, and further comprising the steps of providing to a controller of the ink delivery system an indication representing a total volume of ink withdrawn from the printhead, and decrementing an ink level variable stored in memory in the controller.