smart board 885ix interactive whiteboard system.The screen part of the resistive touch screen is a multi-layer composite film consisting of a layer of glass or plexiglass as the base layer, and the surface is coated with a transparent conductive layer (ITO film), which is covered with an outer surface and hardened, smooth and scratch-resistant. Plastic layer. Its inner surface is also coated with a layer of ITO with a number of fine (less than one thousandth of an inch) transparent isolation points between the two conductive layers separating them. When the finger touches the screen, the two layers of ITO come into contact, and the resistance changes. The controller calculates the coordinates of the contact point according to the detected resistance change, and then performs corresponding operations according to the coordinate. The resistance screen is divided into four lines and five lines according to the number of lead lines. The outer surface of the five-wire resistive touch screen is a conductive glass instead of a conductive coating layer. This conductive glass has a long life and a high light transmittance.