1. Capacitive sensing touch
The capacitive sensing device is a device that uses the current induction of the human body to work. The capacitive touch screen is a four-layer composite glass screen. The inner surface and the interlayer of the glass screen are each coated with a layer of ITO, and the outermost layer is a thin layer of silica. The glass protective layer, the sandwich ITO coating is the working surface, four electrodes are drawn on the four corners, and the inner ITO is the shielding layer to ensure a stable working environment. When the finger touches the metal layer, the customer and the The surface layer of the touch screen generates a coupling capacitor. For high-frequency currents, the capacitor is a direct conductor. Therefore, the finger draws a small current from the contact point. This current flows from the electrodes on the four corners of the touch screen and flows at the same time. The current through these four electrodes is proportional to the distance from the finger to the four corners. The controller calculates the position of the touch point based on the accurate calculation of the four current ratios. The surface of the capacitive touch all-in-one machine is flat.
2. Infrared touch
The infrared touch screen used in the infrared touch all-in-one machine uses a dense infrared matrix in the X and Y directions to test and locate the customer's touch. The infrared touch screen is assembled with a circuit board frame in front of the display, and the circuit board is arranged on the four sides of the screen to emit infrared rays. The tube and the infrared receiving tube correspond one by one into a horizontal and vertical cross infrared matrix. When the customer touches the screen, the finger will block the two horizontal and vertical infrared electronic whiteboard lines passing through the position, so the position of the touch point on the screen can be distinguished. The infrared touch screen is a highly integrated electronic circuit integration product. The infrared touch screen includes a complete integrated control circuit, a set of high-precision, anti-interference infrared emitting tubes and a set of infrared receiving tubes, which are cross-assembled on a highly integrated circuit board In the two relative directions, an invisible infrared grating is generated. The intelligent control system embedded in the control circuit continuously pulses the diode to generate an infrared polarized beam grating, and gradually realizes the function of infrared touch. Infrared touch screen Usually mainly used for touch all-in-one machines with a larger size.
