What Is The Driving Principle Of Capacitive Touch Screens?

1. Projective capacitor contact
Although the basic structure and working principle of a projection capacitive touch screen are the same as that of a four wire impedance film, the projection capacitive impedance film does not capture changes in capacitance between electrodes through a contact field. Generally speaking, when using the capacitive sensor mode, it can almost be called the second extended version of the Touch switch. About the Touch switch.
The projection capacitance mode does not require electrode deformation like the impedance film mode, and can be perceived from the touch pad surface at 10mm. In addition, the surface of the panel is covered by glass scars, which has excellent durability and environmental resistance, but there is no change in electrostatic capacity. The touch panel of the insulator does not work, so it cannot be operated when touched with gloves.
2. Surface capacitance touch
The surface capacitance method is the same as the projection capacitance method. Changes in induced electrostatic capacity. When the projection capacitance method is considered as the four wire resistance film method, the surface capacitance method is equivalent to the five wire resistance film method, and the fifth line is the human body. Composed of transparent conductive film and four corner electrodes. During operation, the four corners of the electrodes are subjected to the same voltage, forming a uniform electrical boundary on the panel.
When all are in phase, the capacitors on the panel discharge. Flow. On the other hand, when fingers touch the touch screen, the capacitor will become grounded. The current flows through the fingers from the four corners, and the current value of the electrode closer to the touch part increases. At this point, only the amount of current from the four corners is measured. This ratio can be used to determine specific parts.