Capacitive touch screen details

The capacitive touch screen is mainly constructed by coating a transparent film body layer on the glass screen, and then adding a protective glass outside the conductor layer. The double glass design can completely protect the conductor layer and the sensor.

         Capacitive touch screens are coated with elongated electrodes on the four sides of the touch screen to form a low-voltage alternating-current electric field in the conductive body. When touching the screen, due to the human body electric field, a coupling capacitor is formed between the finger and the conductor layer, and the current from the four-sided electrode will flow to the contact, and the current intensity is proportional to the distance from the finger to the electrode, and the controller located behind the touch screen will Calculate the proportion and strength of the current, and accurately calculate the position of the touch point. The double glass of the capacitive touch screen not only protects the conductor and the sensor, but also effectively prevents external environmental factors from affecting the touch screen. Even if the screen is stained with dirt, dust or oil, the capacitive touch screen can still accurately calculate the touch position.

      A capacitive touch screen is a transparent, special metal conductive material applied to the glass surface. When the finger is touched on the metal layer, the capacitance of the contact changes, so that the frequency of the oscillator connected to it changes, and the position of the touch can be determined by measuring the frequency change. Since the capacitance varies with temperature, humidity, or grounding conditions, its stability is poor, and drift tends to occur. This kind of touch screen is suitable for the debugging stage of system development.