Products Information

Touch Switch Principle

Touch switch Classified by the switch principle resistive touch switch and capacitive touch switch.

1, the resistive touch screen resistive touch screen is a major part of the display surface with a very good resistance of the film screen, which is a multi-layer composite film, it is a layer of hard plastic plate or glass as the base, the surface coated with a layer of transparent oxide Metal (transparent conductive resistance) conductive layer, covered with a layer of outer surface hardened, smooth rubbed plastic layer, the inner surface is also coated with a layer of coating, between them there are many small (less than 1 / 1000 inches) of the transparent isolation points to separate the two conductive layers insulated. When the finger touches the screen, the two conductive layers touch at the touch point, the resistance changes, producing a signal in both the X and Y directions, which is then sent to the touch screen controller. The controller detects this contact and calculates the position of (X, Y) and then operates according to the simulated mouse.

2, capacitive touch screen capacitive touch screen is a four-layer composite glass screen, the inner surface of the glass screen and the interlayer coated with a layer of ITO (coated conductive glass), the outermost layer is a thin layer of silica glass protective layer , ITO coating as a working face, the four corners leads to four electrodes, the inner layer of ITO as a shield to ensure a good working environment. When the finger touches the metal layer, the user and the surface of the touch screen form a coupling capacitance due to the human body electric field. For the high-frequency current, the capacitance is a direct conductor, and the finger sucks a small current from the contact point. The current flows from the electrodes on the four corners of the touch screen respectively, and the current flowing through the four electrodes is proportional to the distance from the finger to the corners. The controller calculates the four current ratios precisely to get the touch point location information.