Patent ID: 7681968

Claim:
An ink level detecting apparatus usable in an ink-jet printer, the apparatus comprising: an ink tank including a bottom, a ceiling, and a sidewall; a shrinkable ink pack accommodated in the ink tank and including a top surface that moves down substantially evenly as an ink level therein decreases; a fixed electrode disposed on an upper portion of the ink tank; a movable electrode disposed on the shrinkable ink pack to face the fixed electrode at a predetermined distance from the fixed electrode to move in a horizontal direction according to a height variation of the top surface of the shrinkable ink pack such that an overlap area between the movable electrode and the fixed electrode varies; and a guide structure included with the ink tank to enable the movable electrode to slide in a direction that is parallel to the fixed electrode, and the movable electrode horizontally moves along the guide structure and includes a front end in the moving direction that flexibly extends along the ceiling and the sidewall of the ink tank and connected to the top surface of the shrinkable ink pack, wherein the ink level is detected from an electric capacity variation sensed between the fixed electrode and the movable electrode.