Capacitive touch screen structure principle

- Jul 13, 2018-

Capacitive touch screen is a special transparent metal conductive material affixed to the glass surface.When the fingers on the metal layer, contact capacitance will change, that is connected with the oscillator frequency is changed, by measuring the frequency changes can determine the touch location to obtain information.Because capacitance varies with temperature, humidity, or grounding conditions, its stability is poor and drift is often produced.Capacitive touch screen is coated on the four sides of the touch screen with long and narrow electrode, forming a low voltage ac electric field in the conductive body.When touching the screen, the electric field due to the human body, fingers and can form a coupling capacitance between conductor layer, electrode current will flow to the contact from the four edges of bag, and current intensity is proportional to the finger to the electrode distance, the touch screen behind the controller can calculate the current ratio and strength, accurately calculate the position of the touch point.The double glass not only can protect the conductor and capacitive touch screen sensors, more effectively prevent external environmental factors affect the touch screen, even if the screen is stained with filth, dust, or oily be soiled, capacitive touch screen is still can accurately calculate the touch location.