INK LEVEL DETECTING APPARATUS OF INK-JET PRINTER

摘要

An apparatus for detecting an ink level of an ink-jet printer is provided to detect that the ink level reaches a predetermined basis level regardless of a structural deviation and an electrical characteristic deviation by detecting a change of the ink level through an electrostatic capacitance between a fixed electrode and a movable electrode. An ink tank(10) has a bottom, a ceiling, and a side wall. A contraction type ink pack(40) is received in the ink tank. As the remaining ink quantity decreases, an upper plane of the contraction type ink pack is lowered horizontally. A fixed electrode(20) is installed on an upper part of the ink tank. A movable electrode(30) is arranged to be opposite to the fixed electrode at a predetermined distance. The movable electrode is moved horizontally according to a height change of the upper plane of the contraction type ink pack. The movable electrode has a different contact plane with the fixed electrode. Any one of the fixed electrode and the movable electrode has a plurality of fixed wing units, which are arranged at a predetermined gap and are connected to each other, in a vertical belt shape for a moving direction of the movable electrode. The other one of the fixed electrode and the movable electrode has a movable wing unit of a belt shape which is arranged along a parallel direction with the fixed wing units. The remained ink quantity is detected by using a change of an electrostatic capacitance which is detected between the fixed electrode and the movable electrode.