Capacitive touch panel mainly has 4 layers of composite panels. The outmost is glass layer for protection, the second panel is conducting and inducting layer, the third panel is non-conducting glass layer and the inmost is conducting layer which is shielding the electronic signal from inside. The first glass layer and the third glass layer are transparent and completely protecting the most important part of the capacitive touch panel the second conducting and inducting layer. There are four lead wires in the four edges or four angles to detect the contact point position of touch panel. The basic working principle of capacitive touch panel is that there is a long and narrow electrode in each edge of the panel which is forming a low voltage and electric field on the surface. When you touch the panel, the finger and conductor layer will form a coupling capacitor and the electricity from electrodes is going to flow to the contacting point because of the body electric field. The intensity of electricity is proportional to the distance from finger to electrodes. And the controller behind the panel will calculate the exact position of contacting point according to the intensity of electricity. Double glasses construction of the capacitive touch panel not only protects the second conducting and inducting layer, but also prevents the external environment affects on the panel effectively. Even there are filth, dust and oil stain on the surface, the capacitive touch panel still will calculate the exact position of contacting point.
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