Capacitive touch screen using current sensing body work. Capacitive touch screen is a four-story complex glass screen, the inner surface of the glass panel and sandwich coated with a layer ITO (coated conductive glass), the outermost layer is a thin layer of silica glass protection Protection layer, ITO coating as a face, leads to four electrodes on the four corners of the inner layer of ITO is shielded to ensure a good working environment. When the fingers touch the metal layer, the body electric, users and touch screen surface to form a coupling Capacity for high-frequency current, capacitance is directly conductor, so fingers away from the contact point a small current. This current flows from the electrode, respectively, on the four corners of the touch screen, and flows through four electrodes with fingers to four Angle proportional to the distance, the controller through the accurate calculation of these four current ratio, derived position information touch points.

1: Advantages Compared with resistive touch screen and electromagnetic induction plate, capacitive touch screen showed a more favorable performance. Due to be able to sense touch and easy to use. Finger contact with the touch screen and almost no wear and tear, stable performance, the mechanical testing life up to 30 years. In addition, the entire product is mainly composed of a highly integrated chip is only one of PCB composition, fewer components, product consistency, high yield

2: Disadvantages

Using capacitive touch screen of the iPhone is undoubtedly representative of popular benchmark further confirms the advantages of its own. However, fundamental, capacitive touch screen is also faced with the following challenges: As the body becomes a line Points, and thus a serious drift; capacitive sensing technology input or control input point targets in the small and medium size flat panel display performance could be improved (such as phone numbers or enter the English word click on the soft keyboard) when; temperature and Dramatic changes in performance when the humidity is not stable enough, need to be calibrated; not apply to metal cabinets; When the external inductor and magnetic sense, it may cause the touch screen to malfunction.