What is a self capacitive screen?
Self capacitance is based on measuring the capacitance value of a single electrode to ground When the finger approaches the electrode, the human body s capacitance will change the electrode s self capacitance
What is a self capacitive screen?
Self capacitance is based on measuring the capacitance value of a single electrode to ground. When the finger approaches the electrode, the human body's capacitance will change the electrode's self capacitance. In a self-contained touch screen, transparent conductive material is etched onto designated patterns on one or two separate electrodes. When the electrodes are located on one layer, each electrode represents a different touch coordinate and is connected to the controller separately. When electrodes are located on two layers, they are usually arranged as rows on one layer and columns on the other layer, with the intersection of each row or column representing a unique group coordinate. Anyway, the controller of a self-contained touch screen cannot measure the coordinates of every intersection point, it can only measure which row or column it is.
When only one finger touches, the touch screen will work normally. For example, as shown in the figure below, the positions X2 and Y0 of a single touch can be accurately sensed by sequentially detecting all X and Y electrodes. The main drawback of double-layer self capacitive touch screens is that they cannot clearly detect multiple touches by measuring individual electrodes instead of intersections. The touch at points X2, Y0 and X1, Y3 actually generates four point coordinates. However, when using a self-contained touch screen, the defect of two finger gesture operation cannot be completely solved. The secret is in the software - I would rather use vague reporting methods to allow the software to identify the direction of movement of the reporting points. In this case, regardless of whether the two-point touch generates four point coordinates, as long as it can accurately recognize whether those two points are a gesture of moving away or towards each other.
