Ink volume measuring method for ink jet printer with replaceable ink cartridge by measuring capacitance of two electrically conductive layers on ink bag

摘要

A small electrically conductive layer (4,5) is provided on both sides of an ink cartridge consisting of an ink bag with flexible walls. The two layers, separated by the bag walls or the ink form a capacitor whose variable capacitance is a measure of the ink quantity in the bag. When a new cartridge is inserted, the system is calibrated for the individual value of a new bag. An apparatus for measuring the ink volume in an ink cartridge is also claimed.